Chrysalis, Queen of the Changelings and (in her own mind) destined ruler of Equestria, sat at the dining room table and wolfed down a tremendous pile of Yakyakistan-style cabbage rolls.
"MORE!" she bellowed. The pile never grew smaller, no matter how much she ate. "I demand more sustenance! ALL of it, until there is none left for you!"
Alicorn and unicorn stood nearby, watching this display. "...I have found," Luna began carefully, "that the appearance of Chrysalis in one's dream is generally a representation of a loved one or family member who is, perhaps, not as welcome as they should be?"
The unicorn sighed. "...my mother has recently come to visit."
"Ah. And you feel she is taking something from you?"
"Er... my, uh, patience, mostly," the other admitted.
"Are you all right? You seem nervous."
"I just never expected you to visit one of my dreams!"
Luna smiled gently. "No need to fret, child. I am here to help." She peered at the dream-Chrysalis. "I must say, this is an astonishingly accurate likeness."
The alicorn failed to notice the brief pause before her response. "Oh, I was in Canterlot when she attacked and got a good look at her. It... sort of stuck with me."
"Understandable. Well, you'll have to deal with your mother on your own terms, but at the very least you won't have to deal with her here." She passed a hoof through the ravenous changeling, who dissolved into dust. "Enjoy the rest of your sleep... er...?"
"Harmony Delight," the unicorn responded promptly.
Luna's eyebrows raised. "The singer?"
"You've heard of me?"
"My sister has your album..."
"Oh!"
"...though I must admit I find your music is a bit too modern for my tastes."
"...oh."
"But of course that's hardly your fault." Luna added quickly. "Now, I must attend to my other duties. Sleep well, Harmony."
"Thank you, Princess."
Luna stepped out of the dream without looking back, and so didn't see the unicorn, wild-eyed and panting heavily, suddenly lean against a wall, holding a hoof to her chest to fend off an imminent heart attack.
Stepping between the floating balls of light, the alicorn made her way across the Dream Realm. That should be the last of them, she thought, her every sense seeking evidence of a troubled dream. Fortuitously, it seemed to be another quiet night, which meant she could finally address the main issue on her mind. It had taken some effort to bring Celestia back to her senses, but 50cc of red velvet from the emergency supply managed to calm her down enough to listen to reason. Now her sister was sleeping peacefully, and a weary Equestria could finally get a good night's rest.
It would not be entirely accurate to say that Luna was completely recovered - she still sported a moderate headache that tended to flare up whenever she used her horn - but she couldn't afford to worry about that now. Not with an unknown creature loose in the Dream Realm. The lack of any disturbance among the dreamers was a good sign, but she had to remain vigilant; who knew what this entity was capable of?
Perhaps one knew...
After a brief search, she found the dream she sought, and stepped inside just in time to witness a thing she had dreaded for years.
Tirek. Uncaged. And fed.
This, Luna quickly realized, was less of a dream than a memory, and a very recent one at that. She watched in horror as the red centaur traded blows with a small purple figure, their battle ranging across the stone plateau in Tartarus. Watched as he gained the upper hand over his opponent, watched as he incapacitated her, watched as he opened the door to Equestria...
And then the scene shifted, showing the two squared against each other, preparing to do battle.
She nearly leapt out of the Dream Realm altogether to sound the alarm, but the Sunlight streaming through the door told her this had happened hours ago; there was no way for her to prevent his escape now. It was more important to gather information, to better prepare for a future encounter.
Then the two figures began to fight again, and now she noticed things seemed... off. Where were his gouts of fire? His energy shields? Perhaps Tartarus was inhibiting his magic, but the way he moved and fought, it was as if he didn't miss his normal array of powers at all. He fought... well, he fought like nothing Luna had ever seen. "What is going on here?" she murmured.
"He calls himself Spy. And right now he's probably the most dangerous creature in Equestria." Luna turned to see Tempest Shadow stepping through the air and stopping at her side. "Evening, Princess."
"Berrytwist." She looked back at the battling figures. "So, that isn't Tirek? Then, the magic surge we detected..."
"Yup. That was Tirek trying to escape. I don't know what exactly he was planning to do, but he ended up moving his mind to another dimension and switching bodies with Spy."
"Another dimension?! How?"
Tempest chuckled. "Beats me. That's a Sparkle question."
"And so this 'Spy' is the one who attacked me?"
"To be fair, he says he didn't mean it personally."
Luna snorted. "I find small comfort in that. Still, if he's escaped..."
"Oh, don't worry." The scene shifted again, and Tirek's body was sitting dejectedly in a large cage. "It was close, but nobody made it out today. I'm just going over the fight so I can do better next time."
"Next time?"
Tempest smiled slightly. "You never know."
"Why was he even fighting you? Surely you told him we would try to help him."
"Of course, but he's decided he'll leave Tartarus on his own terms or none at all. He was very clear about that."
"Hmm. You say he is from another world. I know Twilight Sparkle has told you about Star Swirl's mirror portal. Do you think he may be a human?"
The purple mare tilted her head. "Y'know, I hadn't thought of that. Maybe? From Sparkle's description, they're bipeds, right? Like minotaurs, but with different legs?" Luna nodded. "Yeah, that could work, considering how he fights. He wasn't one hundred percent comfortable with hooves, I noticed that much." Then she frowned. "But... Twilight described this cozy, friendly school on the other side, and... I don't see Spy fitting in there. He's an assassin."
"An assassin?!"
"So he says. And I don't have any reason to doubt it."
Luna shook her head. "What monster has Tirek brought to Equestria?"
To her surprise, Tempest's expression became rueful. "To be perfectly honest, Princess Luna? He's not that bad."
The alicorn just stared at her. "You cannot be serious."
Tempest shrugged. "Oh, he's a jerk, I won't deny that. He's sneaky and manipulative and fights dirty... but I don't think he's doing it for the wrong reasons. Not by his lights."
The scene shifted once more, and when motion resumed Luna saw the centaur pounding on the little pegasus' cage.
"Once I get this open, fly through the door away from here as fast as you can." The voice was strangely distorted, owing perhaps to Tempest's state at the time of the memory. "Keep low to the ground and look for cover wherever you can. Don't stop for anything."
"Got it! And I'll come back for you when-"
"No! Just go far away, somewhere they can't find you! Don't worry about me!"
"I'm not going to abandon you, Spy!"
"You must! The only important thing here is getting you away from Tartarus!"
Luna's hooves shifted uncertainly. "For her?!"
Motion paused. "For her. He cares about her, Princess. Really cares. Don't ask me why."
The alicorn stepped forward and peered at the centaur, noted the desperate expression on the strange, brutish face. "Tell me more about him."
"Not much to tell, really. I only found out he wasn't Tirek a few minutes before we started to dance. And even if I knew more, I'll bet anything he knows you were going to talk to me, and he'll have a whole different selection of tricks ready for you. Don't underestimate him, Princess. He's smart, and resourceful, and ruthless..."
Motion resumed. "You're not a villain, Cozy Glow!"
They watched as the rest of the scene played out, ending as Cerberus carried the larger cage away. "...and he's got nothing left to lose. That's what makes him so dangerous right now."
Luna didn't respond, lost in thought.
"Look, you don't need to walk into whatever trap he's got waiting for you. I've called Twilight in, and she'll meet me here tomorrow. I think we can get this whole mess straightened out together."
"...I appreciate the advice," the midnight mare said finally, "but... no. No, I've dealt with my fair share of beings from beyond Equestria in my time, and they all meant trouble. I need to judge this 'Spy' for myself. There are just too many unanswered questions." She looked again at the solitary figure. "For instance, how did he feed?"
Tempest frowned. "I've been wondering about that myself. I'm pretty sure he didn't get it from me or Cozy Glow. Another Sparkle question, I guess."
"Then I shall call on her as well. And do not worry on my account, Fizzlepop. There is no trickery he can hope to perform in the Dream Realm that I cannot counter."
"...you're the Princess. I just hope it goes better for you than the last creature I heard with that kind of confidence."
"Oh? And that was?"
Tempest Shadow, former lieutenant of the Storm King, looked at her with an expression of mixed shame and wry amusement. "Do you really need to ask? Good luck, Luna."
It took no time at all to find Twilight's dream; the (second) youngest alicorn craved order and stability, and her dream reflected this, always appearing in the same general area of the Dream Realm. Luna stepped into it and emerged in a vaulted marble library, filled with every book Twilight had ever read, which of course meant that it was packed full to bursting. She made her way along the stacks, keeping an eye out for the flying books that would signal her target's presence (and had no concept of personal space; she wanted to be sure she had time to duck as they went past, rather than make her lingering headache even worse.)
"Oh, hi, Princess Luna! I'm guessing you're here about the whole Tartarus thing?"
She looked down to see a familiar reptilian figure, his arms loaded down with ancient volumes. "Yes, I..." Then she paused and peered at him. It was harder to tell than normal, and the effort made her horn throb, but... "Spike? Is that you? The real you, not just a part of Twilight's dream?"
"Oh. Yeah." He looked embarrassed. "Twilight sometimes pulls me in if she's stressed or trying to figure something out."
The Princess blinked. "...I didn't know she could do that."
"I don't think she knows, either. She never remembers it when she wakes up."
Luna frowned. Not even she or her sister knew all of the limits of alicorn magic, and while she wouldn't have expected Twilight to have any dream-related powers, being able to summon her little brother/personal assistant was so very much in character for the little librarian. "I shall have a talk with her when this is all over, and teach her how to control herself a little better. You deserve to have your own dreams."
"Thanks, I'd appreciate it. For now, though, let me show you to her. I'm pretty sure she'd like to talk to you."
They chatted as he led her through the library, which seemed to have grown considerably since Luna's last visit. "How much did Fizzlepop tell you about what's happened?"
"Well, she sent one of the Guards with a message, so some of it might've been lost in translation, but we heard that there was some kind of magic surge around Tartarus, and then you got attacked in Tirek's dream. And there was something about Tirek not being Tirek? I didn't really get it."
Luna nodded. That matched her initial suspicions from the previous morning; Berrytwist must have sent her messenger long before she'd discovered the existence of Spy. Either way, there was no reason to worry the little dragon with thoughts of an otherworldly assassin in control of Tirek's body. "It is a complicated situation, and I'm still gathering information myself. That's part of why I'm here, in fact."
"Well, I hope Twilight can help you."
She noticed uncertainty in his voice. "You think she might not?"
Spike paused at a door, about to push it open with one foot. There was an odd vibration about the door. "She's... having a day."
The door was opened, and cacophony emerged.
Twilights! Dozens upon dozens of identical copies of Twilight Sparkle filled the room from end to end, and the room even seemed to have been made larger to accommodate them all. Most were either poring over various tomes or were engaged in animated discussion, but a few seemed to be dashing around to no specific purpose and at least one was hugging her knees and rolling back and forth in a corner. Some were apparently experiencing panic attacks or had fainted outright, but there were two Twilights in nurse hats who were tending to them. Their combined conversations (and the occasional wail of despair) shook the walls and floor.
"...have to take into account the resonant displacement effect..."
"...can't possibly have breached the enchantments without..."
"...oh no, oh no, oh no, oh no, oh no, oh no..."
"...respect Star Swirl as much as anyone, but we have to admit..."
"...was just there at the foot of my bed, staring at me..."
"...chances of a complete quantum breakdown are..."
"...and then Celestia won't love me anymore..."
"...of course there's the HIPAA issue to consider..."
"...never even heard of a book called 'What To Do When Your Former Interdimensional Crush Knocks on Your Door'."
"Impossible!"
Luna surveyed the scene, eyes wide. She was no stranger to outlandish dreams, but this... "Spike, what is this?"
He sighed. "This, Princess Luna, is Stage Five Twilighting."
"Stage Five?! I thought it only went up to Stage Three!"
"When she's awake," he corrected her. "When she's dreaming, she has more options."
"My goodness!"
"Just be glad you missed Stage Four. She grows extra heads so she can hyperventilate more efficiently."
"I am definitely going to have a talk with her later on," Luna decided firmly. "This can't be good for her. Thank you for your help, Spike. I'll send you back to your own dream now." Her horn glowed (and she tried to hide the wince), then wisps of moonlight began to surround the dragon, who started to fade from view.
"Princess Luna!" One of the Twilights had noticed her, and she was suddenly standing in a sea of lavender.
"Hello, Twi-"
She was interrupted when one of them flew up and grabbed her face with both forehooves. "We can't let Fizzlepop sing to Tirek!"
"Good luck, Princess!" Spike called, and vanished.
She threw a mildly sour look at the spot he had previously occupied, then turned her attention to the horde before her. "Calm down, Twilight. What is this about?"
"Oh, Princess! I've discovered a massive security problem with Tartarus! If we don't act fast, Tirek could escape again!"
"It's all right," Luna said soothingly. "I just spoke to Fizzlepop and Tirek is-" Well. Not 'secure', if his mind was in another dimension. But she didn't feel this fact would help Twilight's anxiety at all. "...unlikely to find his way to Equestria anytime soon." The tone helped, and the sea of Twilights thinned out a bit as she (slightly) regained her composure. "Now. Does this have something to do with the magic surge we detected?"
"Well, kind of. I'm guessing he made some kind of escape attempt?"
The alicorn nodded. "That's what Fizzlepop told me. But I don't know where he got the magic to even try."
"Oh, that's the easy part," a different Twilight said, waving a hoof. "I figured that out hours ago."
"Do tell."
"Cozy Glow would have had some residual magic clinging to her, from the ritual she used. Tirek could have taken that and used it for... whatever he was trying to do. It probably wasn't a lot, even after a spell that big, but he apparently thought he could make it work."
Luna frowned. "Wait. I'm certain that Tartarus is enchanted against the transfer of magic. How could he possibly take it from her?"
"Nnnnot exactly." Contradicting a Princess clearly pained Twilight. "It prevents the theft of magic, not the sharing of magic. If Cozy Glow just gave him what she was carrying, Tartarus couldn't interfere."
"That seems like a rather glaring oversight."
"I guess Star Swirl just never thought that anyone would want to help Tirek. Anyway, I'm not sure how much he could have done about it. It's like the singing problem, see?"
Luna looked around at the various Twilights, hoping her total lack of understanding would be picked up. It was not. "...I'm afraid I don't. You're going to have to explain."
"Explain?!" one Twilight said, clearly delighted.
"I love explaining!" another added.
"I have a whole school for explaining things!" said another.
And just like that, Luna found herself in a School of Friendship classroom, in a seat that was decidedly too small for her. The rest of the seats were filled by Twilights, who chatted happily waiting for the lecture to begin. She always did love to hear herself talk, Luna thought uncharitably.
A Twilight appeared in the center stage of the classroom, wearing spectacles she certainly didn't need and a mortarboard she technically hadn't earned, although being the world's leading authority on multiple subjects, including the vital field of amicitology, went a long way toward justifying the affectation.
"Harmony," she began, "is the most potent magical force in Equestria. It's not that it's necessarily the most powerful magic, but in any interaction with other magics, harmony always takes precedence. It can still be overwhelmed, but it hits far above its weight class. That's how the Elements can overcome somecreature like Discord, who has effectively unlimited power."
Luna nodded, being pulled in despite being wholly familiar with (and a former target of) the subject. The Twilights around her were studiously taking notes, just for the fun of it.
"But this isn't limited to the Elements themselves, by which I mean the physical manifestation of the six Harmonic Principles. Even the otherwise normal use of magic can be given a little extra 'push' if it's aligned with one of the Principles. My brother's shields are strong enough as it is, but when he's using them to protect his home and loved ones, under the full aspect of Loyalty, he can do truly amazing things. Now, his is an extreme case, and generally this doesn't come up in the day-to-day magic usage of most ponies. But then we get to Tartarus."
Realization dawned. "Generosity."
"Bingo!" She turned to one of the blackboards and, chalk floating in her field, quickly drew a centaur and a small pegasus, then a series of vertical lines separating them. "Normally Tartarus blocks the movement of magic. But the act of sharing with somecreature in need is innately Generous, even if that creature is a villain like Tirek. If Cozy Glow genuinely wants Tirek to have the magic she carries..." She materialized a piece of red chalk and drew an arrow leading from pegasus to centaur, plowing straight through the wall between them. "...it overrides the Tartarus enchantments and allows the transfer. Since it's residual magic and not part of her own personal field, he still can't absorb it directly, but he could use it for any kind of normal spellcraft."
"I see. So how does this relate to singing? That isn't exactly the same kind of harmony that we're talking about."
"True, but it does help a bit. In any case, I'm sure you're familiar with HIPAA."
Luna's brow furrowed. "...hippogriffs?"
"No, no. HIPAA. Harmonically-Induced Performance and Auditory Activity."
It took Luna a few moments to puzzle this out. "Oh! You mean Heartso-"
Suddenly Twilight was there in front of her with a waxen grin. "Harmonically-Induced Performance and Auditory Activity."
"Er... yes." The little alicorn clearly had a death grip on her preferred terminology.
"HIPAAs are a byproduct of strong emotion interacting with Equestria's background harmonic energy," Twilight continued, returning to the blackboard. "Even when it's a painful song, it's a reflection of the pony's natural yearning for the friendship that they lack. So..." She erased everything but the centaur, then drew a pony next to him, with a jagged stump where a horn would be. "Fizzlepop would never willingly give Tirek any of her magic, no matter how generous she was feeling. But if she truly wanted to help him, to establish some kind of connection to him, and especially if their interaction became harmonically charged with multiple Elements..." She drew several musical notes, and through each one an arrow leading from mare to centaur. "...a HIPAA could set off a core essence transfer, tapping into her personal magic reserves and sending part of it to Tirek. Exactly the kind of magic he loves to feed on."
"Wouldn't she notice immediately?"
"That's the thing about Fizzlepop. Because of her broken horn, she can't casually draw from her reserves the way other unicorns can; she can only spend it through violent emissions of electricity. She can't even tell how much she's got. And she's got a lot normally, more than any other non-alicorn I've ever seen. Even if a harmonic transfer gave Tirek half of her supply, she probably wouldn't realize it until she used the rest up. And anywhere but Tartarus, her reserves would automatically replenish long before then anyway."
"I see." Then Luna chuckled. "Well, I'm sure Berrytwist would never lower herself to singing to somecreature like..."
She paused, suddenly remembering why she was there.
...like Tirek.
Oh, dear. She had seemed rather taken with Spy, hadn't she? She hadn't mentioned a Heartsong, but... why would she? They just happened. Had he swayed her to that level of compassion? That was something of a feat in and of itself.
"...Princess?"
Luna relaxed. It had been clear from Fizzlepop's dream that Spy hadn't even known what to do with Tirek's fresh supply of magic. Even if he turned out to be an enemy, he wouldn't be anywhere near as dangerous as a fully-empowered Tirek. No, the fact that he received some of her power was unlikely to be at all important, and would have no negative repercussions whatsoever. "It's nothing. I was just thinking about something. I'll keep your warning in mind, but I don't believe it should be a problem at this point. I do have another question, though."
"...is it a hypothetical question?"
"...let's go with 'yes'."
"I love those!"
"When Tirek tried to escape, could he have done so by using an interdimensional portal, like Star Swirl's mirror?"
Twilight laughed. "Interdimensional? Pff! No! You can't just make an interdimensional portal on the fly! It takes a huge amount of preparation!"
"I see." How had Tirek managed it, then? Had Star Swirl created one within Tartarus all those centuries ago? It seemed unlikely. But Tirek's spell couldn't have pushed past the prison's defenses either...
"I mean, sure, once you set one up they last pretty much indefinitely until you manually close them. And they're surprisingly easy to work with once they're established, needing only a moderate amount of magic to activate..."
Luna stared at her. "Such as the residual magic clinging to Cozy Glow?"
"That'd do it," Twilight agreed. "And it's amazing how simple it is to breach into another dimension, especially if you're not picky about which dimension you want to connect to."
"...I see." Luna firmly added 'Star Swirl the Bearded' to the growing list of ponies she was going to be giving a severe talking to in the near future.
"...but actually setting one up is super complicated!"
"What does it entail?" Luna asked cautiously.
"Oh, the really hard part is establishing a firm anchor point in your own dimension," Twilight explained. "You have to inscribe this big magic circle, and you need several objects of historical significance that the circle can use to establish an unbreakable connection to the home dimension. Nothing like that in Tartarus!"
The midnight mare just watched her, horror slowly growing.
"And of course it takes a huge amount of magic to establish one, although," she leaned in conspiratorially, "if you're feeling sneaky you can set it up so that it automatically pulls in the surrounding magic to power it. Of course, some of it will leak through the portal, but as long as you're careful it won't be too much, and nopony would even notice!"
"...and... if you're not careful?"
"Oh, that'd be bad. You'd see a world-wide siphoning of magic, especially if the exit dimension is one without much magic of its own. Equestria's an extremely high-pressure system, comparatively speaking, so it wouldn't take more than a few days to lose almost all of it. Just like when... Cozy... Glow..." It was at this point that Twilight's mind finally caught up with her own words, and all that emerged from her mouth was a strangled creaking noise.
"Cozy Glow's ritual wasn't just intended to send the magic away," Luna concluded. "It was designed to create a permanent link to the dimension the magic would be sent to."
"That must be it," Twilight agreed weakly. "The circle she used got wiped away when the Tree of Harmony pulled all the magic back, but Starlight got a good look at it, and now that I think about it, her description matches with the necessary spells pretty closely."
"But... no, that makes no sense. Even if this is true, Tirek couldn't possibly have reached from Tartarus to the School of Friendship when he escaped."
Twilight's eyes went wide. "You mean he actually did-?!"
"Hypothetically!" Luna corrected herself quickly.
It didn't work. There was an explosion of new Twilights, each speaking at once.
"The anchor point doesn't-"
"-it can be anything, not just-"
"-doesn't matter where you-"
"-that's how Star Swirl could-"
"-Sirens were banished out in-"
"-needed to be portable, so-"
"-used himself as-"
"-Cozy Glow is the anchor point!"
Luna, slowly becoming crushed by purple librarians, lit up her horn and took a deep breath. "CALM YOURSELF, TWILIGHT SPARKLE!"
The Canterlot Royal Voice, imbued with the magic of the midnight mare's control over dreams, swept through the classroom and banished the duplicate Twilights until only one remained, shivering slightly. Luna pressed a hoof to her temple until the headache faded a bit, then approached the little alicorn and lifted her head. "Yes. Tirek did use the portal to escape, but only his mind made it out. His body is still in Tartarus, and is being guarded quite effectively by Fizzlepop. It's currently occupied by a native of the other dimension, and I'm going to go speak to him now." Though she wasn't at all sure whether Spy was willing to talk with her.
"But... with Tirek on the loose in their dimension... who knows what he could do? We have to help them!"
"And we will," Luna promised. "I have no intention of letting Tirek escape justice. But we need to be prepared for whatever that may entail. And what must we do to be properly prepared?"
"Oh! I can research some ways to foricbly close a portal! And go over some ways to reverse a magical swi-"
A hoof reached out and touched her lips, silencing her. "And what must we do?"
Twilight sighed. "...rest."
"Just so. You cannot use your dreams to ignore the needs of your body. Now, in the morning I'll tell Celestia what we've discovered, and I'm sure she'll send some help. Until then, use this time to get some proper sleep, then meet Fizzlepop at Tartarus."
"You can't order me around," Twilight mumbled. "I'm a Princess too."
The hoof ruffled her mane. "I know, and it's adorable. Take it as a request from a friend, then. All right?"
"...yes, Luna."
At last, Luna stood before the dream floating at what might be considered the far end of the Dream Realm. No explosions or screams this time; what lay within appeared to be a rather cozy room, complete with a fireplace and a large upholstered chair. It was such a peaceful scene that it just had to be a trap.
She took a long, slow breath, then stepped inside.