> Celestia Continues to be a Spider, Though the Fact is largely irrelevant to the Events of this Story
>  by Equimorto
> --------------------------------------------------------------------------

> Chapter the First, in which Things happen
> --------------------------------------------------------------------------

Twilight hurriedly walked up the stairs that led to the castle's library, Rarity closely following her. They finally reached a small wooden door at the end of the narrow spiral staircase, and with some effort managed to open it, strings and web on the other side holding it to its original position. Once it finally swung open, the two found themselves at one end of the library, the room mostly covered in white web.
"Princess Celestia!" Twilight called, as Rarity lifted some loose threads of silk with her magic and studied the fabric.
"Oh, here you are," Celestia replied, descending from the ceiling on a string of her web. She held a book in two of her legs, and kept a pair of eyes on it while the other four focused on the two ponies.
"Your Spiderness," Rarity greeted the arachnid, accompanying the words with a small bow of her head.
"You've received my letter, right?" Twilight asked, panting a little from the recent exertion.
"Of course, my dear," Celestia replied. "I have gathered my guards in the main hall, as you requested. Though, I am afraid I have to inform you that there have been no reports of any friendship problems of any kind." She scratched her head with a leg.
"Are you absolutely sure, Princess?" Twilight began to pace back and forth. "The map explicitly showed the castle. Perhaps the problem is with some other member of your staff, like the cooks or the maids."
"I'll make sure they are questioned as well."
"Good. Well, either way, we're going to investigate the guards to make sure everything's alright," Twilight said in a pensive tone as she headed for the exit.
"Goodbye, Twilight." Celestia waved two legs at the alicorn.
"Your Arachnidosity," Rarity whispered while quickly bowing to the spider before following the purple princess back down the stairs.
"Wait, was that someone? PLEASE, I'VE BEEN TRAPPED HERE FOR MONTHS, SOMEBODY FREE ME!" Chrysalis screamed from somewhere deep in the library. Unfortunately for her, the two were already too far away to hear her.
Twilight reached the bottom of the stairs and walked out, still moving at a rather brisk pace.
Rarity nearly found herself running to catch up to her. "Twilight, dear, don't you think you're being a little too hasty? If the map sent us here we'll find the problem, no need to run around like that."
Twilight huffed, still keeping her gait. "I'm sorry, Rarity, but we've got no time to waste. Less than a week, if my calculations are correct, and Sombra will come back. We can't afford to stay here too much if we don't want to get caught unprepared by that."
Rarity wiped some sweat away from her forehead. "Do you really believe that prophecy will come true? I think you might be stressing yourself over nothing. It's probably made up."
"Yeah, like with Nightmare Moon," Twilight retorted.
Rarity bit her tongue. "Touché," she admitted. "What was up with that anyway? The whole 'stars aiding in her escape' thing, did you ever figure out what actually happened?"
Twilight took a deep breath, closing her eyes for a moment while still moving forward. "Rarity, now is really not the time to make me think about one of the greatest unresolved mysteries of pony history. We have more concrete matters at hoof at the moment."
Rarity rolled her eyes. "Sorry," she muttered.
Twilight slowed down, having finally reached the large doors leading into the hall where Celestia had gathered her guards. She took a deep breath, and opened them with a wave of her horn, then stepped inside.
The large room was filled with rows of guards, all standing in place and waiting for her arrival. They all looked up at the sound of the doors opening, and straightened a little when they saw the alicorn enter.
Twilight walked up to a small platform that had been set up on a side of the room, followed by Rarity, and turned around to address the guards. "You are all aware of why you have been called here, right?"
The guards nodded. "Yes ma'am!" a stallion standing at the front replied, his armour identifying him as a captain.
"Good. I have been informed by Princess Celestia that she has already asked about this, however I will ask again. Please, do not hold back or lie, no one will judge you for this and it's of the utmost importance that we get to the bottom of this as quickly as we can. Have any of you experienced friendship problems in the recent period of time?" Twilight asked, running her gaze over the faces of the guards to catch signs of hesitation.
Silence reigned in the room for a few long seconds.
Twilight quietly sighed. "I sincerely hope this is the truth. If any of you see someone struggling with friendship-related issues, please contact me. You're free to return to your daily activities. Any questions?"
A single hoof was nervously raised, but Twilight noticed several other guards behind the pony were inciting him to ask that question.
"Yes?" she asked, looking at the guard.
"Why is, ah... Why is Princess Celestia a spider?" the stallion reluctantly asked.
Twilight blinked once. "I don't have the faintest idea," she replied.
A low murmur spread through the crowd.
"Any more questions?" Twilight surveyed the room once more with her gaze. "No? Well, then I will be going. I hope you'll all be prepared to face against King Sombra once he returns sometime next week. I will now be checking the kitchens if anypony needs me." She turned around and walked down from the platform, then somewhat defeatedly headed for the exit, head held low as the white unicorn followed her.
"Come on, dear, don't be so gloomy," Rarity said in a tentatively cheerful tone, prancing to surpass Twilight and talking to her by turning her head back over a shoulder once they'd exited the hall.
"We're all doomed," Twilight replied, "why even try at this point? We've already fallen behind on the schedule, we'll never make it in time. We'll just waste our energies and fail to be sufficiently prepared when Sombra comes, and then be defeated. It's all useless."
Rarity stopped and looked at the alicorn. "Twilight, what are you saying? This isn't like you at all, dear."
Twilight stopped and sat down. "Why even bother with anything when we're bound to fail? We should just lie here and wait for the end, at least we won't suffer more than we need to." She let herself fall over the red carpet and remained there, half-closing her eyes.
Rarity was beyond preoccupied at that point. "Twilight, what-"
"Princess Twilight!" a voice called from the end of the hallway, belonging to a young stallion. He ran up to the duo, panting a bit. "I bring news from Her Royal Eight-Leggedity Celestia. She says neither the cooks nor the maids report problems of any sort." He looked down and noticed the alicorn's condition. "Oh dear, what's happening to her?"
"You heard him, Rarity." Twilight's tone was deep and sluggish, her breaths unnaturally slow and profound. "We failed, there's no more time. We should just sleep now." Her eyes fully closed and her body went fully limp against the red fabric covering the floor, her breathing slowing even further.
"Twilight!" Rarity desperately called, trying to wake her friend by shaking her unconscious body in her hooves. "Twilight!"
> Chapter the Second, in which more Things happen
> --------------------------------------------------------------------------

"Changeling venom," the doctor announced, throwing a glance over his shoulder to the sleeping body on the bed, "we'll have to wait for it to naturally be disposed of by her system, that'll take a couple of weeks given how much was injected in her. It's not the typical variant, but there's no doubt about what it is. We could synthesize an antidote, but we would need venom from the changeling that bit her in the first place to do that." He began to walk towards the exit.
Rarity looked between him and Twilight's sleeping body. "Is there..." she tried, words getting stuck in her throat.
The doctor turned towards her. "Yes? Did you say something?" he asked, adjusting his glasses with a hoof.
"I... No, it was nothing," Rarity said, defeatedly lowering her head.
The doctor turned and walked away. "Visiting hours end in thirty minutes, please leave the room by then," he reminded the two while going through the exit.
The sound of the door closing echoed in the room, and Rarity sighed, looking at the floor. A wing tentatively reached her back, and she looked at her side. "I'm sorry you had to be dragged into this, dear. Thank you for helping me with carrying Twilight. And with finding this place, I would have probably gotten lost, shocked as I was."
The pegasus smiled at her. "Oh, don't worry. She's a princess, after all, I was just doing my job." He stroked her neck with his feathers. "I'm terribly sorry about this happening to your partner, I hope she'll get better soon."
Rarity half-smiled, looking back at the floor with a bitter expression on her face. "It's not too big of a problem. At least, it wouldn't be, Twilight being out of commission for a while, if it was just that. The problem is that it's happening now, and now's really not the time for something like that." She wistfully looked up at Twilight.
The pegasus sighed and did the same. "I'm Smoke Screen, by the way. I already know your name's Rarity, no need for introductions there."
"Well, nice to meet you, Smoke Screen," Rarity replied, a little more cheerfulness in her tone.
Smoke Screen adjusted in his seat, moving his grey tail out of the way from below him. "So, Rarity, what brings you and Princess Twilight here to Canterlot? Is it a simple visit for pleasure's sake or are there orders from above?"
"A mission," Rarity replied, "the Cutie Map sent us here and... Wait, if you didn't know about it, then when you said 'partner' earlier... Oh gosh, did you mean... Me and Twilight..." Rarity's face coloured red.
Smoke Screen looked at her, a little taken aback. "Oh, sorry, it's just... Rumours circulate here among members of the royal staff. Is it something I shouldn't know, or is it just-well, incorrect?"
Rarity regained some of her composure. "I-Well-It's not... We're not together, like that. I mean, I like her, but not-Like her, you know? I'm not into mares, that's all."
It was now Smoke's Screen's turn to blush. "Oh I'm-Sorry, about that... Well, I mean-" he blushed even harder "-I'm not sorry about that, you know what I meant, it's not like I'd be sorry to know you weren't into stallions and I-Eh-" He bit his tongue to stop his rush of words, and if anypony who didn't know him had looked at his face at that moment they wouldn't have known it should have been pale custard and not blood red.
Rarity chuckled, and moved a strand of grey mane out of the way of Smoke's face.
The stallion looked at the floor, occasionally throwing a furtive glance up at Rarity. "So, you were saying about your mission?" he tried.
"Oh, yes. I believe you know about the Cutie Map, correct?"
Smoke Screen nodded. "I've heard of it, yes. I don't know much about the specifics, but I think I get the general idea."
"Good. As I was saying, the Map sent us here in Canterlot, so there's supposed to be a friendship problem of some kind for us to solve. It was already a pretty bad time for something like this, given what Twilight thinks will happen in about a week, and then we couldn't find anything once we actually got here, which just made things worse." Rarity looked once more at the alicorn's body. "Twilight being poisoned like this right now is just the worst possible thing!" she dramatically added, leaning back in her chair and posing with a hoof on her forehead.
"Can I..." Smoke bit his lower lip. "Can I ask what's supposed to happen next week?"
Rarity brought a hoof up to her mouth. "Oh my, you haven't heard?"
Smoke Screen shook his head.
Rarity furtively looked around. "King Sombra is supposed to come back," she said in a low tone. "At least, according to Twilight's calculations."
Smoke Screen gasped. "King So-" His voice was muffled by Rarity holding up a hoof to his mouth.
"Shh," the unicorn said, "it's supposed to be a secret only for the princesses and the Royal Guard. We don't want somepony finding out about it and then creating mass hysteria by spreading the rumour around the population, do we?"
Smoke Screen gulped and nodded.
Rarity removed her hoof.
The pegasus leaned forward. "King Sombra is coming back?" he asked in a whisper.
Rarity nodded. "At least, that's what Twilight thinks will happen, and she's usually right about this sort of things."
Smoke Screen looked around the room, then leaned a little closer. "Do you think whoever poisoned Twilight did it on purpose so she wouldn't be able to stop him when he comes back?"
Rarity frowned in thought. "That's a possibility, yes. But who would want something like that?"
"Perhaps the two things are unrelated," Smoke admitted. "Princess Twilight does have many enemies, after all. Still, this might be quite the problem. Whichever the case, we should try to find the culprit, don't you think?"  
"We should," Rarity agreed. "Oh, but what can I do? How am I supposed to search the whole castle for both the friendship problem and the one who poisoned Twilight? I can barely get around here, and Celestia's guards have already failed at one of those things, and last I heard they were failing at the second too. This is just terrible!"
"Well..." Smoke Screen offered her a hoof. "I can help, if you want. I know my way around the castle pretty well, and this seems like a serious issue. What do you say?"
Rarity looked at his hoof, surprised. "I mean... Isn't this going to interfere with your job?"
Smoke Screen gave a brief laugh and a small shake of his head. "My job is to serve the princess, and"- he looked at Twilight -"she looks like a princess to me. Plus, I don't think her Giant Spiderosity is going to notice the lack of one single member of her staff." He smiled. "And even if she does, I think this is more important. And, well, likely more entertaining as well." His voice dropped to a whisper. "Don't let it get out that I said this, but working under Celestia is boring. I have to stand around doing nothing all day, and the rare times I have to do something it usually involves looking at inventory lists at best. Count me in on this thing."
Rarity hesitated one moment longer, looking between him and his hoof, then she smiled and offered her own.
Smoke smiled back, and they shook hooves. "Do you already have plans for where to start?" he asked, drawing back his leg.
Rarity put her hoof to her mouth in thought. "Well, we need Twilight to wake up if we want to stand a chance against Sombra, and we need her awake for the friendship problem as well. So first things first, we should find out who poisoned her."
"Sounds like a sound plan to me," Smoke replied.
Rarity sighed. "If only I had any idea of where we should actually start searching." She looked up. "Any ideas?"
Smoke munched on his lower lip. "I... Okay, here's my train of thought. Changeling venom can usually knock somepony out in a matter of seconds. The version that hit Twilight is different though, it's clearly slower. Well, unless you're the changeling, but we can't really work under that assumption."
Rarity drew back for a moment at the words, a quizzical and somewhat offended look in her eyes.
"Here's the thing though, it's still changeling venom. It can't be that different. It probably works in a matter of minutes, not hours. And if it doesn't, well..." He sighed and looked down. "If it's actually that slow then it would become impossible to go back far enough. Too many variables, too many ponies she might have come across, so there's no point. So if we want to have a chance at solving this we have to assume whoever poisoned Princess Twilight did it here in Canterlot, after you two arrived. What that means is that we should go back through your path and look for clues there." He looked back up. "So?"
Rarity frowned in concentration for a moment. "You do have a point, darling. We can't afford to go back too much. Even if we just assume it was on the train ride, that's hundreds of ponies from all over Equestria. It would take days to check all of them, plenty of time for the culprit to hide. So we have to focus on Canterlot and the palace." She got up from her chair. "Let's do this, we've got no time to waste."
Smoke Screen nodded and got up as well.
Rarity walked up to Twilight. "Hang in there, darling," she said. She turned and walked out of the room, Smoke following behind her.
> Chapter the Third, in which yet more Things happen
> --------------------------------------------------------------------------

"This is the spot, right?" Smoke asked, studying the red carpet below him.
Rarity nodded. "Roughly, but yes." She focused her attention on the ground as well. "What... exactly are we looking for?" she asked after a few moments.
Smoke suppressed a grin. "Anything unusual, really. There is always the possibility that Princess Twilight was poisoned with regular venom, through some sort of trap set up here. But it's very unlikely, she would have probably noticed she'd been stung or something of the like. And even then, any signs of the trap would probably have already been removed. Still, doesn't hurt to check," he explained.
Rarity chewed on her lower lip, wincing slightly. "We should have been more careful."
"Don't worry about it. It's not a mistake when you couldn't have known what was going on at that point. And Princess Twilight would be just as much to blame for not notifying that she'd been stung by something, if that really were to be what happened," Smoke reassured her.
Rarity grimaced. "She really doesn't take her role as princess as seriously as she should. An attempt at harming her like this was bound to happen sooner or later."
The pegasus looked up at her, still somewhat focused on the carpet. "She has decided not to keep any stable body of guards, right?"
Rarity nodded, a touch of annoyance towards the alicorn creeping onto her face as she thought about that.
Smoke gave one last look at the floor, then dismissed it and began to walk down the hallway, tracing the path Twilight and Rarity had taken backwards. "That certainly complicates things. If, say, she was poisoned through some food she ate. Having a guard taste her food for her would have prevented that."
Rarity walked up to him, and curiously asked, "Does Princess Celestia have an official food tester or something of the like?"
"She doe-" Smoke stopped. "Well, she doesn't now, not any more. Her own poison melts through pretty much anything she eats, so it neutralises whatever harmful substances may be in her food. But she did have one. Though it was never revealed who it was, and voices said it was a different pony every time. It's the risk with keeping guards, you got to make sure someone else doesn't buy their loyalty."
"That does sound like a problem, yes," Rarity agreed.
The pegasus stopped and pointed a hoof at a corridor. "You came from there, right?"
Rarity put her hoof to her chin, thinking for a moment. "Yes, that should be it. That there is the entrance to the hall, right?"
"Yep. I don't think we need to check that one, it was a room full of guards, after all," he said, heading down the corridor. "Although..." He stopped in front of the large doors.
Rarity stopped at his side. "Something the matter?"
Smoke clicked his lips. "Well, if we assume Princess Twilight was poisoned before coming to this room, and that's what we're doing, since no one would be foolish enough to attack her in a room full of guards, then that raises a problem. How much control did the culprit have over the time it took for the venom to take effect?" He looked at Rarity.
The unicorn raised a hoof to her lips, pondering. "They couldn't have known how long Twilight's speech would last. And if she'd passed out in the middle of it, in front of a room full of guards..."
"It would have caused quite the commotion, right?" Smoke finished for her.
Rarity frowned in concentration. "But if the risk was there, wouldn't it have been beneficial for them to run away after poisoning Twilight, instead of being there when it happened?"
"There is always the chance that the venom responded to a trigger, and that they were following Twilight to activate it at the right time," Smoke explained. "But in the more likely scenario in which that wasn't the case, then it would have been beneficial for them to be there. In the confusion, it would have been easy to manipulate the guards into following false leads, or to slow down the investigations. Or even just to see what their plans were."
"But wouldn't they have run the risk of getting exposed that way?" Rarity asked.
"If they were in the room," Smoke replied, "then they were most likely pretending to be a guard. Changelings are experts at manipulating others and at impersonating, and if they got into the room they probably took the place of an existing guard who's now locked somewhere. Without proper training against mind-reading spells, the guard's memories are completely open to the changeling, it would be almost completely impossible to tell them apart without spending a large amount of time being personally close to then. And that opens you up to their hypnosis."
Rarity shivered. "It really is a good thing that they are on our side now."
"Not all of them, it seems," Smoke grimly commented. He took a step forward, and opened the doors, beginning his search for clues.  
Following behind him, Rarity asked, "Do you think... Do you think this might be Queen Chrysalis's doing?"
"Unlikely," the pegasus replied, giving a brief look at the steps of the platform before moving on to the centre of the room. "This doesn't seem like her style. She would never accept leaving Princess Twilight like that, either she'd capture her or confront her directly. Leaving her to sleep and then disappear? Doesn't sound right, she'd at least try to replace her. But I don't think she'd go after her first, personally."
Rarity walked up to him, her eyes scanning the floor as she attempted not to focus on how the tapestries' colour didn't quite match that of the decorations on the ceiling. She asked, "What do you think her plan would be?"
"First, approach Celestia while she's unguarded, possibly during her sleep," he replied, moving on to examine the nearest wall. "Use a disguise to trick her, maybe Princess Luna or Princess Twilight, one that makes her relax. Then, try to hypnotise her." He lifted an arras to look behind it. "At that point, assuming she falls, either take her place or manipulate her from behind. The next step would be taking care of Princess Luna and Princess Twilight, as they might be able to figure out something is wrong, it's debatable which one she should go after first but knowing her it would likely be Princess Twilight, just for the sake of revenge." He let go of the arras and started to walk towards another one. "Once she falls, capture and hypnotise the other as well. And then move on to the Crystal Empire to finish the job, taking both Princess Cadence and Prince Shining Armor. At that point she'll have gotten rid of all the major threats to her."
"What about young Flurry Heart?" Rarity asked, "Or Starlight, or those who helped her defeat Chrysalis? And wouldn't it be much harder to keep things a secret without changelings to use to replace other ponies?"
Smoke stared at her. "Look, we thought about that plan years ago, okay? Things changed since then."
Rarity paused. "You'd thought about it?"
Smoke nodded, moving to look behind the second arras. "The Royal Guard isn't as incompetent as some ponies say it is. Far from it, actually."  
"Then how did Chrysalis manage to capture all the princesses?"
Smoke let go of the tapestry. "Because they didn't expect there to already be changelings amongst them. Chrysalis knew their every move in advance, she'd acquired quite a bit of useful information from Prince Shining and with time it paid off, allowing her to replace members of the Guard without anypony noticing."
"I... Interesting..." Rarity replied, seemingly focused on something else other than their conversation. After a moment she shook her head and looked down from the spot her eyes had drifted to.
Smoke screen noticed this, and curiously asked, "Did you find anything?"
"Oh, no, nothing important, probably," the unicorn dismissively answered.
Smoke looked around himself. "Well, I'm not finding anything here, so if you've got something it's always worth a shot."
Rarity bit her lip. "It's that one spot on this arras here. It's up there, see?" she asked, pointing a hoof upwards. "It's a little more faded than the rest."
Smoke squinted, staring in the direction pointed at by Rarity's hoof, then took flight to give a closer inspection. "You're right!" he said, floating at the tapestry's side, "It is a little more faded in this area." He put a hoof under his chin. "Say, what causes fading like this?"
"Well, usually it's exposure to sunlight," Rarity answered. "But, you know..." She gestured around the room.
Smoke chewed on the inside of his cheek for a moment. "Unless..." He looked back at the faded area for a moment, then moved upwards and began to inspect the ceiling.
Rarity followed him with her gaze, perplexed. "What are you-"
"Ah!" Smoke interrupted her with his half-yell.
"Found something?" asked Rarity with sudden excitement.
"It looks like it!" Smoke replied, a side of his face pressed against the ceiling. "There's a hole here! It's pretty small, and you can't spot it looking up from down there, but it's definitely big enough to spy through. It looks like there's a room on the other side, though I can't see much."
Rarity's face lit up in realisation. "So maybe they didn't need to take a guard's place to spy on Twilight."
"Exactly," Smoke replied, coming back down. "I think I know where that room's supposed to be, it's hidden behind a wall but I've been there a couple of times. And I know for a fact that hole is not visible from the other side the way it looks like it should be, which means that even if it might have already been there it was opened recently, and possibly left open by someone who left in a hurry. If they left any traces, it's there we should look for them."
Rarity energetically nodded. "Let's not waste another minute then."
Smoke nodded in agreement, and the two quickly walked out of the hall, the pegasus leading the unicorn down a corridor and up a flight of stairs.