Harry Potter and the Prancing of Ponies

by The Guy Who Writes

Rehabilitation 14.4: Constant Vigilance

"Congratulations, Ms. Sparkle," said Riddle in a tone that didn't sound like he meant it at all. "You have finally managed to maintain an adequate block against my attacks."

'Adequate', he says, Twilight thought to herself, grumpily and explicitly. I have NO doubt his world would consider me WELL above 'adequate'.

It's not often that Twilight dislikes a tutor for holding her to the highest standards so she'll achieve the greatest mastery. In fact, this might be the first time she's ever disliked a tutor for doing that.

It's true that Riddle is himself a master at this task, but he's also a taskmaster. He's a perfectionist and a perfection-demander. A slavedriver in almost every way, except that Twilight isn't technically a slave. Twilight has the free will to quit at any time or ask for a slower pace in lessons.

She did not ask to slow down. Lives are on the line. They are constantly on the line, every second of every day, until Twilight solves the Stone.

So she didn't ask to slow down, and she didn't complain out loud.

Unfortunately, Riddle could still hear her when she complained on the inside – he could literally see her unspoken thoughts every time he read her mind – and while sometimes he would stop and reconsider his behavior, other times he would just smile and keep doing the thing.

When the disincentive for failure is your own private thoughts being read by a pony like Riddle, anypony would want to learn Occlumency as quickly as possible. No, she does not trust him when he says things like "I only saw information on my other selves," or "I only searched for another memory of Starlight Glimmer."

She needed to be able to stop him, so she spent all of her free time learning the standard block as described in the textbook, practicing as much as possible in her free time – as much as it is possible to practice without a Legilimens to test you.

But of course it didn't end once she mastered the textbook instructions. The standard block, as it's standardly taught, is no match for a competent Legilimens.

When a pony like Riddle is using Legilimency to not only read your thoughts, but actively reshape them to make you believe that you are on fire, or that you are late for your test and you forgot to study, or worst of all, that your friends are all dead…

Actually, worst of all was when he instilled the thought of Twilight being dead, and none of her friends attended her funeral because they were happily going about their days because they didn't care about each other anymore. He did this the first and definitely last time Twilight would ever request that he 'hit her with something serious', because she wanted to know how much of a negative impact a Legilimens could have on your thought processes if they went all-out. (She did not consider that he still might have been holding back, and he only gave her a tame trauma he thought she should be able to handle.)

In the face of things like that, Twilight learned very quickly indeed how to defend against intrusive thoughts that weren't. Hers. No matter how much they seemed like they were hers. This came with the upside/downside of treating all thoughts as suspect when she's in Riddle's presence, even thoughts that are truly hers. These lessons are forcing her to become more aware of her own mind and how it operates.

And now, finally, she has managed to defend against two straight hours of probes and sledgehammers and sly slip-ins and mere distant observations and whispering thoughts from a master Legilimens.

Her standard block is still a rock; she still pretends to be a simple sort of pony in order to prevent her mind from being read. But that simple pony is the most rigid and sturdy and unchanging and uncurious pony in the world, her simple thoughts fully under control and immovable by any outside impulses. At least, that's how her block operates when she's fully focusing on it, and after two weeks of bitter work she has finally reached the level where she can focus on it for hours at a time.

Now she's finally getting to move on to the next stage: Actually working on the project.

"I will not require perfect Occlumency from you before we proceed to the project," said Riddle. "But I will require you to achieve something else before we proceed."

Or not.

Twilight almost groaned. "What now?"

"I will require you to maintain an Occlumency block – perfect or not – at all times, in all places, in front of all ponies. Even in front of your closest friends, even when you are feeling safest, even when you are completely alone, even when your eyes are closed. And you will do this for the rest of your life."

…

…

…

…

…

…

"WHAT?!"

It was her first accidental use of the Royal Canterlot voice.

---

"Now that you are ready to continue," said the calm, cool voice of Riddle, after Twilight had finished having an episode.

His darkly shining example of stoicism was a blessing and a curse. He doesn't warn Twilight before saying completely insane things, but he also doesn't budge or get worked up himself as she freaks out, which helps her calm down faster.

"If you get into the habit of letting your defenses slip," said that stern voice, "if you regularly let your guard down, that weakness will eventually be exploited. All it takes is a single moment of vulnerability to die or fail. It is an axiom of battle magic, and Occlumency is just as much a part of battle magic as the Killing Curse. If your shields are down for whatever reason and a disguised or hidden Legilimens exploits that weakness, out go your deepest, dangerous secrets."

Twilight's mind wanted to reject the reasonable-sounding argument. She wanted an out. Because she did not want to be constantly pretending, constantly faking, constantly lying for the rest of her life.

"…Couldn't I just stun and arrest anypony who attacks my mind?" And she found one. "I can detect all the different kinds of Legilimency attacks at this point. Unless you've been holding back."

"I have not. But what if they touched your mind so lightly and so briefly you didn't notice? On the other hoof, what if they are a Dark Lord strong enough to resist your offense? What if they simply teleport away after getting whatever they could? What if they decide to overpower you, capture you, and torture you? Most competent criminals have a fallback plan for the moment things go wrong. If someone can use Legilimency, they will be somewhat competent. Your default should be constant vigilance. Focus on assault and arrest after assuring your own armor."

Twilight stared at him for a while. "So… let me get this straight," she said eventually. "In all your time here, in all your time in Equestria where nobody even knows what Legilimency is, you've never let your guard down? You've always been pretending to be someone else?"

She knew she was asking the question to avoid thinking about her daunting future, but it was still an important one to ask.

Riddle gave an easy shrug. "As a teacher, I rarely require of others what I have not first done myself."

"That doesn't answer what I asked."

The corners of his lips twitched upward. "For over the past forty-five years of my life, even when I was trapped and bodiless for ten years and I had absolutely no logical or plausible or even paranoid reason to fear a Legilimency attack, I never once dropped my Occlumentic guard. Both out of habit and out of principle."

…

Twilight thought about it.

…

She thought about it some more.

…

…

…

Eventually, she said, "Okay, about the bodiless thing, what? And about your Occlumency practices, that couldn't have been good for your mental health."

Riddle's eyebrows furrowed. "Whyever not?"

Twilight almost attempted at an answer, although… "Intuition," she ultimately articulated instead. "The important thing is, now I've got to learn how to do that too." Hopefully in a way that doesn't have a habit of constant deception. "And what about my other question?"

He denied her request in a dour voice. "Declined." Then he seemed to reconsider. "Until you learn perfect Occlumency, and even then perhaps not." He shook his head. "But for now we shall focus on your practical defense. I will begin testing you as I tested Mr. Silver. Expect a Legilimency ambush at any time, in any locale, from anyone. You must survive ten consecutive Legilimency plots. If you fail one, your test score will reset to zero, and you shall have to resist another consecutive ten. Also, I might still test you randomly after that."

"Do I get to fight back?" she asked. "Does stunning you and preventing your escape count as a success, if I happen to leak anything?"

His eyebrows rose. "I suppose you could try." A light grin. "That might even make it more interesting. But such battles are violent, you know, and many of my plots shall occur in public locations, surrounded by fragile property and fragile ponies. On my end, whenever I am performing these tests I shall try my best to prevent others in Ponyville from realizing anything unusual is going on. After you detect intrusion… if you detect intrusion, and if, after you detect it, you try to protect your information the hard way, so be it. But once the 'secrecy' of the plot is blown, I might escalate as well, as any true criminal would."

Twilight took a little bit of time to absorb the constraints of the test. She asked a few more questions and got a few more answers. Every answer was in line with what Riddle had already said.

"Do I have a choice about when we start?" she finally asked. "Can I ask for you to give me a few days to think about it and prepare?

He gave a disappointed sigh. "I suppose I do require your consent. Waiting would certainly be less immediate work on my end." He was frowning heavily as he said that. "But be warned, if you wait a week, that would be a week of your mentor giving me her favor and aide – on a demanding project that requires a daunting amount of royal resourcefulness and her full attention – in exchange for her student asking for some time off. Or did Celestia not inform you of our deal?"

Princess Celestia had told Twilight the vague outline of the deal.

The Princess was doing a massive practical favor for Riddle, a favor she was absolutely certain could not be turned to evil ends, so in return he was providing his own massive practical favor: helping Twilight's research.

"She told me the general outline of the deal," Twilight said, wearing her own heavy frown. "But she wasn't very specific. What is she doing for you, exactly?"

"Hmm…" he said, seeming to think about it. "In the same way that I am and shall be teaching powerful magics to someone important to her – for the sake of you and your entire world – she is and shall be teaching powerful magics to someone important to me. For the sake of me and mine."

Twilight took a moment to absorb that. And then a few moments more to think about what it meant. And then she applied the new knowledge to her original problem.

"Does the pony she's teaching get time off?"

"That one may ask for as many breaks as he wishes. But he will have no friends to relax with, no frivolities to enjoy. Other than light conversation with strangers he only just recently met, and myself whom he hates."

Putting two and two together…

"Is it that being trapped in the Mirror?"

"Yes."

"Can you tell me more?"

"Yes."

…

…

…

"Will you tell me more?"

"Not with an open-ended prompt like that."

"Is there any particular reason you're being evasive about it?" she asked without thinking, though on second thought it was thankfully a closed prompt.

"Yes."

After a pause to think in advance if her next prompt was open or closed, Twilight asked, "May you please tell me that reason?"

"If you're asking whether it's classified, it's not. At least, not from you. Otherwise I would not even have hinted. As I said, I can tell you. But it is still good practice for powerful wizards to offer their students riddles instead of answers. Consider it a part of your Occlumency lessons. You are excellent at solving abstract puzzles, but you do not yet excel at outwitting other intellects."

Twilight spent a bit more time asking questions and getting more vague and unhelpful answers. As she did, she debated in her mind if she should allow him to start his 'Legilimency plots' right away or if she should give herself some time off first.

Eventually, she realized that if things get too stressful during the tests, or if she fails and her 'plot counter' resets to zero, she can ask for a day off then.

"I can start right away," Twilight decided.

"Very well," said Riddle. "Be prepared, Ms. Sparkle. I doubt it will be pleasant for you."

Twilight prepared herself…

And jumped a little when the clock struck the top of the hour.

Riddle turned around, opened the door to the lab, and left the room, just like he did any other day that his allotted time to the project was over.

Guess they aren't starting today after all.

---

Later that same day.

Ah, the spa!

After such a stressful series of weeks, Twilight was really looking forward to this. She'd scheduled the whole thing herself this time, without Rarity's help. And she had scheduled it weeks ago.

Back then, past-Twilight had suspected future-Twilight might want a relaxing afternoon after working with Riddle for that long. And if it didn't turn out to be stressful after all, well, a day at the spa is a day at the spa. That had been her reasoning.

Thank you, past-Twilight, she thought with a light smile, for being so thoughtful to future-Twilight. You didn't know how right you were.

"Appointment?" asked Lotus Blossom, one of the day spa's two co-managers.

By habit, Twilight waited for Rarity to answer, then kicked herself when Rarity raised an amused eyebrow at Twilight.

"Um, yes," said Twilight. "Twilight Sparkle, party of six."

"Right this way," said Lotus, a bit more briskly than usual, before she began leading them to the hot room, home of the big bath tub.

Today wouldn't be anything complicated, since it was her first time doing the ordering for anything at the spa. Just a long, lazy soak in warm water that's filled with a special solution for their hooves and fur and manes. It would give Twilight plenty of time to catch up with her friends and not think about anything else.

Mental health is incredibly important for all researchers. That's, like, rule #1 of being a consistently good researcher.

"It's ready when you are," said Lotus, gesturing at the bubbly bath, to which Twilight and her friends immediately started trotting. "Oh, and Ms. Sparkle?"

"Yes?" asked Twilight, looking back.

Upon meeting Lotus's eyes, she received a sudden 'bombardment' style Legilimency attack, the kind that's ruthlessly obvious and can get precise information quickly, if you can't raise a reflexive shield in time, or can't reinforce your existing shield fast enough.

Thankfully, Twilight had not quite dropped her mental guard, she was not quite alone with her friends yet. And even though she's only been learning for two weeks, part of her Occlumency lessons – even before today – had involved the art of always being aware of her 'surfaces' and maintaining her shields for longer than Riddle's allotted lessons.

And so Twilight's shield was not bashed in by the sledgehammer. She reinforced it in time. She did not allow any of her true thoughts to be read.

"Good job," said 'Lotus' in a mildly approving tone, wearing a slight smile. A second later, she closed the door, leaving Twilight and her friends alone.

"Good job?" asked Rainbow Dash. "What was she talking about?"

Plot number one, apparently, Twilight thought. Did he swap her out when she wasn't looking? Was he pretending to be her from the start? Did he get Lotus Blossom's consent for whatever he did?

Twilight shook her head and sighed. "It's nothing, Rainbow. Don't worry about it."

"Well, come on then," said Rarity. "Our coats won't soak themselves."

"They will once we're in the tub," said Twilight.

And once they were in, it was pure, bubbly bliss.

"If you don't mind sharing," said Rarity's voice. "You seem stressed, darling. Is there anything on your mind?"

Twilight had her eyes closed, and there was a flash of an impulse to talk about her work, but she couldn't. Then she realized there was something she could sort-of talk about, so long as she was careful.

"Yeah. Riddle Tome is not a pleasant pony to be around. I don't know how Princess Luna does it."

Pinkie Pie's voice piped up. "Oh! You mean Mr. Spooky Alien Meanie-pants?"

Hm… Twilight had almost forgotten how much her friends sorta-kinda knew about Riddle. Maybe she could say a bit more, vent a little, without straying too close to his secrets.

"Yeah. Circumstances have forced me to spend a lot of time around him lately."

"Circumstances, hmm?" asked Rarity, sounding interested.

Applejack didn't seem to notice or care about the precise flavor of Rarity's curious tone. "Why spend any time 'round him anyway, Twi? If'n he's such a pain in the flank to be around, just… stop bein' 'round him all the time."

"It's not that simple, Applejack."

"Not that simple, hmmm?" asked Rarity, sounding even more interested.

Again, it went over AJ's head. "Ain't no reason to be 'round him if you don't want to. This is Equestria, ain't it? Freedom of assosh-" she paused, tried again, "freedom of assoshee-" again, the pause. Then a huff. "Well, yah got freedom to stop bein' around a pony if you don't like 'em."

Twilight wished the real world was as simple as legal documents. "It's work-related, Applejack. You can't just go and kick Big Mac off the farm if he ever starts being a pain in your flank."

"Well that's family," said Applejack. "A bit different, that is. 'Sides, he ain't never been a pain in anypony's flank, far as I remember."

"What I meant," said Twilight, allowing a bit of her frustration to get to her, "is that if Big Mac was just a normal old employee- no, if he was the farm's co-owner, that's a better way to put it- if Big Mac wasn't your brother, or your family member, if he was the co-owner of the farm, and he does better work on your farm than anypony else, a hundred times as good as the next best employee, his work is so good that he's irreplaceable and you'd go out of business if he stopped working, and he never violates your co-ownership contract in any explicit way, but you still really really don't like how he choses to exercise his freedoms whenever the two of you have to talk about normal, work-related business, like he always puts you down and insults you every time your work doesn't match how good he thinks your work should be, and maybe he's right to hold you to a high standard but he doesn't have to be so mean about it all the time, THEN what would you do?"

Applejack had blinked multiple times during that question. "Ah… could you repeat that, Twi?"

She did, conveying it better the second time around, and Applejack seemed to understand.

"Weeeeell," she drawled eventually. "Not sayin' Mac would ever be like that fer real- but if he was really that bad, I could always fire him. Or if he was the boss, I could leave. Or if we were co-owners, I could demand we split the farm and go our separate ways. Not sayin' I'd like to, not sayin' I want to, but the option's always there."

"Even if you go out of business the next day because his work is vital to the entire farm, even your half?"

"Yep."

"What would you do after you went out of business?"

"I'm an Apple," said Applejack proudly. "I'll find honest work somehow."

"And you'd still go your separate ways even if it was a family member?"

"Especially if it was family."

That got her some odd looks. Especially from Rainbow Dash, the element of Loyalty.

"Hey, it ain't a real family if yer forced to be together. We're born family by blood; we stay family by choice, not 'cause we have to. 'Sides, ya don't hold lower standards fer family than yer employees. 'Specially fer how they're talkin' to ya an' how they're treatin' ya. I might take a decent bit of lip from customers an' let it slide. Might even take some lip from a farmhoof every now 'n then. But I don't take lip from family 'n friends, if'n we ain't just shootin' the manure and that lip is honest and mean and it don't stop when ya ask 'em to stop and they got no good reason for it."

Now it was Twilight's turn to spend some time absorbing her friend's words, and ask for a bit of clarification until AJ conveyed it a bit better.

"Thank you, Applejack," she said eventually. "I think that helps."

"Does it?" asked Rarity, sounding more interested than ever.

Twilight gave an exasperated sigh. "What is it, Rarity?"

Rarity's smile looked like she was suppressing a great deal of smugness. "Well, darling, I just always find it curious when a mare spends so much time around a stallion she claims she doesn't like. An attractive, powerful, high-class, single pony with exacting standards. Exactly like you are, except he also has a dark, mysterious past."

Twilight's jaw had already dropped by the time Rarity had finished talking. In genuine indignation and shock, because that was an entirely wrong read of the situation.

And perhaps it was her recent Occlumency lessons; perhaps it was her growing maturity at being forced to deal with ponies who really, really don't think like she does; but for whatever reason, she didn't act like her old self might have acted.

"You know what, Rarity," said Twilight. "I can't even muster the energy to get frustrated. Here is the honest truth, and Applejack can stop me if I lie. I am not attracted to him that way. Or any way. AT ALL. I am not attracted to him precisely because of his dark, mysterious past, and his dark, mysterious present, and worst of all, his dark, mysterious future. Also, the whole 'alien' thing. It's like…" she had trouble putting it into words. "You remember how he killed Tirek?"

With one exception, her friends all glanced at each other nervously. Especially Fluttershy, who had heard the explanation about the Killing Curse. They looked at Twilight and nodded.

Rarity was the exception, who went on undaunted. "Yes, to save Luna, Twilight. That's actually where I was going with this. Everypony in Canterlot knows he and Princess Luna are an item. It's an open secret."

Even Twilight, who was not overly familiar with high-class social games, knew that 'open secret' is code for 'blatant rumor'.

"So if you are developing feelings for him," Rarity advised, "it could cause a scandal. Alien or not, he's stallion enough now, at least as appearances go. Celestia knows I tried to woo him, once. Quite the mistake that was. I was just saying to be careful not to repeat my mistake, darling."

"Rarity…" Twilight said, again getting that feeling of frustration and again dismissing it. "Let me just finish what I was going to say, please?"

Rarity's eyebrows rose. "Very well, darling."

Twilight took a deep breath. Now, how to say this in such a way that it does not violate her contract to not reveal his secrets…

"There's a reason he's able to swat the world's most powerful Dark Lords like flies," she finally settled on saying. "And you might imagine that reason makes him romantically interesting, Rarity, but when you know what that reason actually is, it doesn't. It really, really doesn't. The reason he can swat Dark Lords makes him the last pony you'd ever want to 'woo'. And I'm not allowed to say what that reason is to you, so please don't ask. Only Fluttershy can know, because she stuck around to sign the contract that Luna had us sign after the Tirek incident. And the rest of you didn't. So I can't talk about it. Okay?"

"Twilight," said Rarity, in a tone of dreadful seriousness and importance, a true friend's imploration. "Look me in the eyes, darling."

Twilight did.

"Even if I'm wrong about romance, I can still tell you're bothered by something you're not saying. You can be honest with us about what's really bothering you," she said. "We're your friends."

And in her state of warmth (and vulnerability), Twilight's mind almost went to her frustrations with the Stone. Because Twilight almost missed the subtle Legilimency probe directing her thoughts that way.

A probe coming from Rarity.

From 'Rarity'.

"DOES THE TERM 'PRIVACY' NOT MEAN ANYTHING TO YOU?!"

Her second ever accidental use of the Royal Canterlot Voice.

'Rarity' reeled, as if hurt by the outburst. "I'm sorry, darling," she said, sounding genuine. Twilight could now clearly hear the over-the-top performative tinge to her tone of voice, but honestly Rarity always talked that way, so it's no wonder Twilight missed it. "I didn't think it was private private, I just thought-"

In a flash of further frustration at new lies getting piled on top of existing lies, Twilight fired off the Changeling-reveal spell at 'Rarity', the first 'BE REVEALED, LIAR!' spell that came to mind that might actually do something.

And in a flash of green fire, 'Rarity' was not revealed to be Riddle Tome. She was revealed to be an ordinary-looking Changeling.

"Time Out!" the Changeling immediately said in a bit of a panic, shrinking away and sinking a bit into the hot tub. A green-glowing horn manifested a parchment directly in front of Twilight, who almost reacted badly. "Signed permission from your Princesses!" it continued. (It had a female voice, but you could never be certain about gender based on that, where Changelings are concerned.) "Please don't hurt me!"

That pleading, pathetic tone at the end, which might or might not have been genuine, did a good job of snuffing out Twilight's righteous indignation either way. She grasped the document in her magic. Honestly, she didn't need to read it, or double-check if it was a forgery. She certainly will double-check it at a later point, but she knew who was behind this, she personally had given him permission, she just didn't suspect that he'd go to lengths like this. At least, not so soon.

Also, how did he get a Changeling to do Legilimency? Is he teaching them how to do it on the side? Did he already teach them a while ago? He said Princess Luna is the only other native Equinoid who's been instructed in Occlumency/Legilimency. Was he lying?

But no, none of that took immediate priority.

"Don’t panic, girls," Twilight said to her shocked friends, and looking at Rainbow Dash in particular. "Princess Celestia…'s arrangements caused this to happen," she said, which was as honest as she could get without revealing anything. "This is just a test to make me a better Alicorn." Again, kind-of-sort-of true. It was as honest as she could get, under the circumstances

She got a various noises of understanding from her friends – a quiet "Ooh," from Fluttershy, a "Neato!" from Pinkie Pie, and a "Cool," from Rainbow Dash.

"What ain't ya tellin' us, Twi?" asked the Element of Honesty, the only one who was still skeptical.

"Things I can't tell you because I literally can't say it and I'll get paralyzed if I try. Important, work-related stuff. I really wish I could say what, but I can't. I'm being as honest as I can. Maybe I could be even more honest if I were smarter, but it's really hard to explain anything when I'm bound not to say a lot of stuff."

Applejack sighed. "Alright. 'least ya have a good reason." The farm-mare looked at the Changeling. "Only thing I wanna know is… where's the real Rarity?"

That was what Twilight was going to ask next, yes. She looked to the Changeling. "Is there any way you can reassure me that Rarity is okay?"

The Changeling looked a bit relieved. "Yes, of course!" A small, hoof-held mirror was drawn from the water (was the Changeling keeping it in one of its hoof holes?). The Changeling tapped the mirror's surface, which changed to show an image instead of a reflection. "Here, this is a live image."

Through the mirror, Twilight saw Rarity sleeping peacefully in her room.

But present-Twilight doesn't quite feel reassured by that. She's been getting more paranoid than usual lately. And more curious. Which enabled her mind to find good questions quickly. "How are you getting this image?"

"Um…" said the Changeling, a bit nervously. "There's a 'ling on-site, keeping her asleep. It's a two-way mirror."

"What's a two-way mirror?"

"Riddle Tome's invention."

Twilight sighed. His blatant idea theft that makes him seem more brilliantly inventive than he actually is, more like.

But again, not important. Priorities.

"Can you ask the 'ling on the other side to show themselves?"

"…Um, sure."

Without any words being exchanged or pause for communication – right, Hivemind – the image turned to show a Changeling whose horn was glowing. The image-Changeling waved a hoof and whispered 'Hi!' in a female-buzzing voice, a voice that came through the mirror.

"Are you feeding right now?" asked Twilight, the next question that came to mind.

"No!" the Changeling in the tub denied instantly. "Strict orders from the King are still in place. No parasitic feeding. Voluntary love only, no stealing anything meant for others." Then, in a lower grumble, "This operation is taking a lot of energy, though."

Twilight's curiosity almost ran away with her, the impulse to ask 'How so?', but then she remembered what the purpose of this entire outing was even supposed to be in the first place.

"Well, here," she said, giving the Changeling a hug. "Thank you for helping me become a better Alicorn."

The Changeling was surprised. Their fearful, tense expression melted into relaxed relief and bliss.

It was only then that Twilight remembered that theory about Changeling evolutionary biology causing them to get actually genuinely really scared for their lives whenever they're revealed as Changelings mid-disguise, and she tried to send a bit of reassuring 'it's okay' feelings mixed in with her thanks, if the Changeling could feel that.

"Now I don't mean to be rude," Twilight said five seconds later, "but could you please leave?"

The Changeling shook themselves out of their stupor. "Um… yes, sorry." They extracted themselves from the pool and quickly buzzed to the door, a glow of their horn drying them off first so they could actually fly.

When the door closed, Twilight had an impulse to sink tiredly into the bathtub, as deeply as she could go, but first she realized she should cast a few general privacy spells, just to be sure they were really alone. When her wards turned up nothing, then she collapsed into the comfortable water. She gave a deep moan as she did.

"So," said Rainbow's unsure voice, though Twilight had her eyes closed. "That was a thing."

"Sure was," said Applejack.

"Yepperino," said Pinkie Pie.

Fluttershy's voice continued saying nothing, and Twilight knew that if she looked, she was sure she'd see Fluttershy trying to sink into the bubbles and the water and shy away thanks to that extremely unsettling experience.

"Say Applejack," said Twilight, not opening her eyes, just speaking upward and knowing she'd be heard. "Why couldn't you tell the Changeling was lying?"

Twilight heard a frustrated grunt come from Applejack's direction. "That's the thing, Twi'. Never could tell a 'ling from a real pony when they're disguised. Well, wait, that's not true. Sometimes I could, sometimes I couldn't. Always felt like a complete manure-shoot."

Twilight heard Rainbow giggle.

"So it's intermittent," Twilight said. "That's… interesting," she said. She almost said 'frustrating', but then her curiosity had taken over.

They're not enemies with the Changelings anymore, so she doesn't have to view it as a problem that has to be solved quickly, she can just view it as a problem to be solved eventually. Which means there's no reason to be frustrated about it. Not that getting frustrated helps when you're trying to solve quickly.

"When you could tell it was a Changeling," she said after a few seconds of normal, not-frustration-tinged thought, "was there anything that all those times had in common with each other?" Which is the best question to ask in order to solve the problem, now that she's thinking clearly. "Like, it was only strangers you didn't know?"

There was a brief pause of silence, the sound of Applejack thinking. "Honestly Twi, I wasn't payin' close attention. Been years since the… ah, what do they call it… the great disguise, or somethin'."

"The Great De-Disguisening," Twilight offered.

"Yeah, that. Haven't had many Changelings pretendin' to be ponies lately. Haven't really thought about this in years, for the most part."

"Did you have any theories for why your element could only detect Changelings sometimes? I mean, back before the Great De-Disguisening."

"I jus' figured they can mess with my element whenever they want, an' sometimes they forget."

"Hm," said Twilight, having already considered and mostly-dismissed that theory. "I'm starting to suspect that it's not that… whimsical."

Maybe it was true for the Queen/King, but normal Changelings? Again, maybe, but she was going to start considering other possibilities more strongly now. Why would an entire species maintain techniques to counter one magical artifact that hasn't been in use for a thousand years?

"I don't think they're deliberately fooling or failing to fool your element," Twilight said out loud. "I don't even think it's conscious. On their part."

"Boring!" Rainbow Dash declared. "Let's talk about something else already. I hate talking about Changelings."

That's… a bit judgmental of her, Twilight thought. Right?

"Because they're not loyal?" she asked.

"Oh, they're loyal alright," said Rainbow. "To each other. Nopony else."

There was a long, awkward pause.

"They kinda had to be," Twilight said eventually. "But they're getting better now, right?"

"…Maybe," said Rainbow. "C'mon, something else. New topic."

That's when Twilight got an idea for a bit of fun. "Sounds to me like something a Changeling would say," she said in a slight sing-song voice. "Wanting to not talk about Changelings and all. Don't you think, Pinkie Pie?"

The party pony caught on instantly. "Why, I sure do, Twilight! Only a meany Changeling in disguise wouldn't want to talk about Changelings. Right, Fluttershy?"

"Oh!" said the quiet voice of Fluttershy, who had been giggling to herself. "Um… yes?"

"Well?" said Twilight to Rainbow in a voice of over-the-top accusation. "What do you have to say for yourself, 'Rainbow Dash'?"

Rainbow appeared honestly appalled at the accusation. She seemed at a loss for words. That is, until Fluttershy whispered something to her that Twilight didn't catch. ("Just play along. It's fun.")

Rainbow's eyes widened a bit, then pointed an accusing hoof. "How do I know you're not the Changeling, 'Twilight Sparkle'? Throwing around accusations and all. That's exactly what the real Changeling would do."

"Very, clever, 'Twilight'," said Pinkie, seeming to play the part of the whimsical onlooker who believes whomever spoke last. "Taking charge so nopony suspects you. Pinkie Pie sees through your disguise with her pony eyes!"

"I revealed the Changeling plot!" Twilight objected in genuine indignation.

"That's exactly what a mastermind Changeling would do!" Rainbow declared. "So none of us would suspect you!"

"I- I-" Twilight floundered for something to say. Then she gave a groan of defeat. "Now I don't like talking about Changelings."

There were giggles from everypony else.

"Everypony knows if this was a real situation I'd just cast the Changeling reveal-spell, right?"

Nods all around.

"Wait, actually, casting it myself might not reveal me if I were a Changeling. Hm… Does anypony know if a Changeling can cast it on other Changelings without un-disguising themself?"

Shaken heads. (Accompanied by confused looks, because they didn't understand the question.)

Or pretend to cast it, Twilight just realized, which would be a very good way for a Changeling mastermind to make normal ponies think they're safe. "Ha! See? I have just performed the spell, everypony. No Changelings here!"

Wow, there are a lot of ways to lie. And if not for all her recent training with Riddle, she probably wouldn't have seen these possibilities so quickly. No wonder Changelings weren't outed until a poor leader came around.

Say, whatever did happen to Chrysalis, anyway? Probably Tartarus, but Twilight doesn't remember any word about an escort. Did Princess Celestia keep the convoy super-secret to prevent a prison-convoy-escape-attempt because of the hivemind thing?

"Looks like ya got a lot on yer mind lately," said the voice of Applejack.

"Tell me about it," Twilight grumbled.

"Well come on, sugar. Just relax and give yer poor brain a break."

"I'm trying, AJ. I'm trying."

Surely it was safe to drop her Occlumency barrier while she had her eyes closed, right? She'd already revealed the Changeling, and besides, there's no possible way to do Legilimency without eye contact.

Riddle claimed that he bluffed a few powerful wizards into believing he could do it without eye contact – a fact that definitely qualifies as one of his secrets. But for real, actual Legilimency, you need real, actual eye contact. Face-to-face, no medium or barrier between. Except perhaps a transparent pane of glass at most, such as a pair of glasses.

Of course, Riddle's instructions were to keep her Occlumency barrier up at all times going forward…

But Twilight's intuition told her that it wasn't mentally healthy to always, always be pretending to be somepony else. Even if that somepony else is a simple rock. Maybe especially so.

What she really needed to do was ask Riddle to give her a day to ask Princess Celestia or Luna about her intuition before trying to take and pass his exam.

Yes, that's it! That's exactly the correct thought. So obvious in retrospect, but Riddle's pressure and meanness can make it hard to think about all the alternative possibilities out there.

And so, after considering the problem, she decided to relax that part of her mind as well, the part responsible for Occlumency barriers and for thinking about the problem. If she fails, she fails, but she will not take risks with her own mental health.

She'll eventually find a way to honestly and truly pass Riddle's tests, of course. But she's not just going to go ahead and do exactly what Riddle did with his own mind. That's just asking for trouble.

And she's not going to call off the test, either. She's not a quitter, and she wants to see if she can approach it a different way.

Even without Occlumency barriers fully prepared or raised at the time of a Legilimency attack, it's still possible to prevent anything important from leaking if you're quick enough – a reactionary block, not a constantly-active one.

If you don't have shields up, but you're not thinking about anything important and you notice a sudden probe, you can seize control of your own thought processes before they turn to anything dangerous. The Legilimens will still have seen your honest thoughts, but not about anything important.

Will Twilight actually pass this way? Probably not. Riddle will probably consider it failure if she's not actively pretending to be a rock when he ambushes her. But it's worth a shot.

If nothing else, Riddle's upcoming tests will show her the kinds of ploys a Dark Lord might try to ambush-Legilimize her. And that is useful information regardless of whether she passes or fails.

Whatever method Twilight does end up using to protect her secrets at all times, it will have to work in the face of those 'plots'. That much is still true.

So she'll keep the test going, but she's lowering her barrier for now – at least when her eyes are closed, or when she's only with friends and family, or when she's in private.

And as soon as she gets home she'll promptly send a letter to the Princess(es?) asking for a private audience.

"Look like ya finally relaxed, eh Twi?" asked Applejack's voice. "I can see it on yer face."

"I finally did," said Twilight, opening her eyes and meeting AJ's.

"Y' wanna talk about it?"

Twilight considered trying to explain it in abstract without violating any secrets… where would she even start? Her mind glided across the important topics she wasn't allowed to talk about-

And then she realized that track of thought wasn't hers, that her thoughts were being directed.

She broke eye contact with AJ and groaned.

"You fail," said 'Applejack' in a vocal tone and timbre that didn't fit Applejack's drawl at all.

The other mares looked a bit confused at that.

"I know," said Twilight. "I expected to fail when I decided I'm going to ask the Princess for advice before I do anything with my mind that might make it more like his."

The other mares glanced around unsurely.

"Okay," said Twilight, standing up a bit, dripping warm water. "Keeping in mind that I know how to cast the Changeling reveal spell, I'd like a show of hooves. How many of you are Changelings?"

There was a pause. Four hooves of four different colors were slowly raised.

"May I ask you all to kindly undisguise yourselves so I don't have to cast it?"

Green flashes of fire all around. The water didn't seem to have any effect on the lime licks of flame as they traveled down their fur and into the water. There was no steam or sizzling or prevention of ignition.

"May I also ask how you are all so good at pretending to be my friends?"

Another pause, now accompanied by a low, buzzing hum.

"But my king," one of them whispered harshly. "What if she-" she stiffened, cutting herself off. Then she slumped. "Yes, sir."

Twilight raised an eyebrow.

A clearing of the throat. "It's ancient Changeling deception magic. When we put your friends to sleep, they're not actually asleep, they're in a dream-like state where they think they're going about their day. We link up a 'ling's mind with theirs, the 'ling disguises as them, and then basically the 'ling takes a step back and just lets the pony's mind use their body all day. It's like… turning a pony into a Changeling for a day, only the pony doesn't realize that's what's going on."

"Wait," said Twilight. "You're saying I kind of was with my friends just now? Like… you were all remote-control puppets of my friends minds?"

"…Basically yes," said the Changeling after a pause.

That… was both incredibly fascinating AND incredibly weird at the same time.

"What happens when the puppet thing ends?" Twilight asked the obvious question.

"Oh, the mission's blown. Their minds are going to fill in the blanks on how they got home from the spa, probably decided to take a quick nap, and they'll wake up a bit later, or something like that. Sometimes we have to go the dream route, make 'em think it was all a vivid dream."

Do the Changelings have access to whatever magic Luna uses to influence dreams? And a version of the False Memory Charm Riddle mentioned?

Twilight suddenly realized that, when Riddle said Celestia's censorship of mind magics has had certain negative effects on Equestria's ability to defend itself, he might have been talking about this. Changelings, obviously, would have a lot of mind magics at their disposal.

"If we're careful," the Changeling went on, "the linked 'ling can influence the pony a bit, like we did to look you in the eye. We can make 'em walk a different path to work in the morning, or say a sentence they wouldn't have thought to say on their own, but they'll still say it once 'they' think of it, that kind of thing."

"Thank you," said Twilight, "that answers the next question I was going to ask. Is there anything else you can volunteer before I start rudely probing for more details about your ancient magic?"

"Um… king's orders are we can tell you anything you want to know about it. So… brief history lesson, the reason this spell operation was invented was… well, acting is hard. And if you're trying to pretend to be somepony else who actually exists, your acting is always going to be imperfect no matter how good you are. This way is a lot safer, on every front. The pony remembers a lot of what happened, so they don't miss a day of their lives like if we swapped them for an actor. Plus there isn't the messy situation of mismatching memories. The downside is it takes a lot of Love to fuel the operation, you have to be really sure you can get even more Love in exchange. Well- I mean, that's how we used to operate. We weren't taking any of your Love for your friends just now, or their Love for you, no matter how delicious it smelled! I mean… um…"

"I understand," said Twilight. "I actually think that answers the rest of the questions I was going to ask about the spell." She didn't expect them to share details about the spell structure and casting instructions. She was more interested in the theory anyway. "Now, may I ask how much of this was Celestia's idea? Also, how precisely Riddle is involved in all of this? Was it him or you who read my mind just now? And if it was him… how?"

Another pause filled with a nearly subaudible humming buzz, which Twilight was beginning to understand as an indication of Changeling telepathy.

"Sorry. Can't say."

Twilight considered pressing for more, but decided against it.

And even though she was still highly perturbed to say the least – to learn that Changelings could almost literally become the ponies they were disguised as, with enough preparation time and a little foalnapping – that didn't mean she was inconsiderate in the face of the consideration of others.

Assuming they're being honest about not stealing any ambient Love, despite being extremely tempted; assuming they're being honest about not using this operation in general to steal any Equestrian Love ever since the change in leadership and the Great De-Disguisening…

"Can I ask everypony to share their names?"

This time there was a pause that didn't seem to be the result of a private hivemind conversation, just awkward nervousness.

"Um… Nympha," said the one who had answered all her questions, the one who'd been pretending to be Applejack, still speaking in a female voice.

"Cave Crawler," said the one who had been pretending to be Rainbow Dash, speaking in a male voice.

"Moss Jumper," said previously-pretending-to-be Pinkie Pie, male.

"Web Watcher," said former-Fluttershy, female.

"And," said Twilight, "can everypony on the other end of the two-way mirrors introduce themselves? And can you get the Changeling who was pretending to be Rarity back in here, so I can ask for their name? And Lotus's replacement too, if she was a Changeling?"

There was again the undertone of nervousness as the Changelings quickly and efficiently did as requested.

"Thank you," said Twilight sparkle, surrounded by Changelings in a warm bath. "Now, everypony come closer," said the Alicorn.

Nervous glances all around, and a bit of inching towards her.

"Everyling, please come here." She was being carefully reserved in her emotions, so as not to give away her plan. She used Occlumency to help her do it. She also addressed Changelings by name if they weren't quite close enough for what she intended to do.

When they all were right next to her, looking incredibly nervous and afraid, she used her alicorn wingspan to engulf them in a hug. She closed her eyes and dropped her barrier, just in case that interfered with her emotional output, which it probably did.

"Thank you all for helping me with my important project. Thank you for revealing yourselves when asked, and for sharing your names, I know that was difficult for you. And thank you for sharing an incredibly interesting and private magical secret with me. I promise I will never use it to harm your hive, or allow it to be used to harm your hive, if I can help it. Now, I have one last question before I encourage you all to leave so I can let myself experience all the negative emotions that I don't think you want to be 'tasting'. Okay?"

"Sure, anything for you," said Cave Crawler, a look of bliss on his face. That earned him a light bonk on the back of his head.

"What question?" asked Nympha, who'd done the bonking.

"Can Changelings cast the Changeling revelation spell on other Changelings without revealing themselves in the process?"

Comments

[Poparakelis]

This is like 4 dimensional chest

[The Guy Who Writes]

11766282
Well, a certain chess player DID inspire this idea. Not 4-D, but still clever.

[Fireeaters]

I wonder why the requirements of perfect occulumens are too strenuous and objectionable for twilight, but acceptable for harry and hermione

[Fireeaters]

And if there were any breakthroughs between the rehabilitation chapters and the present day chapters, if they should have been taught to harry's dad

[The Guy Who Writes]

11766369
Not too strenuous. She’s just in a hurry to get on to the project, and a normal barrier is sufficient to protect her info. I guess I didn’t explain that well enough. She’ll learn Perfect Occlumency, probably faster than any who came before if she gave it her all. But time spent on Perfect Occlumency is time spent NOT solving the Stone.

I write after I had her spend a whole chapter with her friends and at the spa.

[Booster Spice]

I thought the changelings trying to interact with Pinkie would have the hardest time, unless theyre getting backup or Pinkie is just taking them easier on them?

The game would only be relatable to manure if a pony name of Crapper invented the tippler toilet in Equestria also? Comes from a corruption of game Crabs and it ahs other names and history.. Wikipedia Craps game.?

[carlarc]

Love Twilight being Riddle's apprentice. Love the immediate 'everyone is a ling' plot. The changeling magic is great too, love to see those guys get some love. The little 'was she keeping it in her hoof holes?' thought was amusing.

I do kinda wish more Equestrians had agency in the fic, it almost feels a bit... stale? With Celestia, Luna, maybe Twilight, and somewhat the Chaos Gods as the only equines providing a counterbalance to Riddle. I don't mean in terms of magical or physical power necessarily, just agency in the story. The ling plot, while great, does somewhat highlight this with the elements of harmony not even being themselves.

[The Guy Who Writes]

11766953
The way I envision it, the Equestrians have plenty of agency, just not within the Riddle-relevant plotlines, for the most part. They're out in the world doing canon stuff from the show. In order to have agency in Riddle's story, they have to have the kind of agency that, as you point out, Twilight and Luna and Celestia have. The kind of agency held by Dumbledore and Harry, and as a distant fourth, Severus Snape. Otherwise they don't even register on his radar except as distant annoying blips, or as pieces on the gameboard to be moved into position. The Changelings have registered as pieces, the Elements (especially Pinkie) have registered as annoying blips. From Riddle's perspective.

Plus, I tried to use this chapter to highlight how something like 99% of native Equestrians, especially ponies, simply don't want to interact with Riddle. They have freedom of association, and he's mean. So they won't go out of their way to interact with Riddle unless it's necessary business, or it's short enough that they don't get to know him, or unless they register on his radar as interesting enough to pursue further interaction. But then he would pursue interaction with them, not the other way around, which brings us back to the original problem of him only finding sufficiently-intelligent-and-competent ponies interesting.

[carlarc]

11767283

Of course. He's awful, almost nobody wants to be near him.

But only part of my complaint was diegetic - I was also speaking about the non-diegetic as well, with a cast of Equestrian characters that, I worry, may be a tad too small for these rehab episodes. Just some thoughts.

Oh CRAP I just realized. You've GOTTA show Lyra's reaction to the humans when they arrived on Equestria. That's going to be a fun moment.

[Fireeaters]

Depending on when hpatmor happens, I bet harry's dad has heard of the beginnings if the wh40k franchise

[Black--Soul]

How mean to ask a huge question without giving the reader the answer

[Black--Soul]

This chapter shows how easy Equestrias second Changeling invasion could have succeeded so swiftly.