He never stopped doing his job. To slack off would be to invite retribution, and they would bring his schemes to an end before they even properly began. The ponies would be distracted, eyes on the joyous wedding of two of their own, one a royal, so a big deal.
All Chrysalis had to do was replace that royal. She, that royal, was nice and sweet and easy to get along with. As targets went, a fairly straightforward one. All she had to do was play the part.
Perception snorted softly, having difficulty imagining Chrysalis pretending to be a sweet creature. Still, her husband to be was the one holding up the defensive barrier. Why, you might ask, would the changelings leak they were going to attack?
Chrysalis, of course. She gave bad orders, put 'lings in the wrong place, and they got spotted. She yelled at them afterwards, Perception heard, but the damage was done, and they erected the shield.
That was alright. He had his own agents, and they hadn't messed up yet. He just needed the perfect moment, and one ally on the other side. Mark against the ponies, only one of them seemed to even doubt the pony stand in. Chrysalis wasn't even doing that good of a job, but only one of them was noticing it. At least she was noticing it a lot.
Better luck, she seemed to be a pony of some import. Not a royal, but linked to them, and that was good enough, right? So when she, Twilight, was starting to get upset, he approached. She was slumped over a table, her friend having just abandoned her. "Rough day, isn't it?" He casually hopped up on the other side of the table from her. "It should be a joyous one."
Twilight pricked an ear, looking up from her boneless state on the table. "I'm sorry?"
"I'm being rude." Perception put a hoof on his fuzzy and fake chest. "Perception Gap, and I believe you."
Twilight pushed upright against the table. "You do?"
One of those magic things. Being there to trust in someone, even just to claim it, can really make someone's day. Pony, human, changeling, doesn't matter. "I do. She is not acting like herself. Completely out of character."
"Right?!" she blurted, coloring swiftly afterwards. "I don't understand... how only I see it... Everypony else is so swept up in the wedding, they're ignoring what's right in front of them!"
Like a changeling chatting directly with her? Perception wouldn't bring that up. "I know what's going on... and I have an idea how to make the others see."
Twilight's ears danced, hope shining in her eyes, but it dimmed. "Excuse me... but I don't know you. It's nice to meet a new pony and all, but... who am I talking to?"
"Perception Gap," he repeated. "And noticing that is my specialty." He pointed to the mark on his rump. "Noticing this is right up my alley."
Twilight leaned to the side to spot that mark. "Oh, a perception gap!" She actually understood the symbol! The first besides him to do so. "I see. Your cutie mark isn't lying to you, but how do I prove that and close that gap?" She brought her hooves together in a silent meeting.
"Now you're talking." He smiled in what they meant to be a kind way, but perhaps a step or two in a cunning way, an honest mistake really. "I know where the real Cadance is hidden." He would, he was the one that pointed out where she could be tucked away where none would find her, unless he told them, of course. Or if Chrysalis sent anyone else down there. But why would she do that?
Oh, how her eyes sparkled. "You do?! Where?" She leaned forward enough to shove several plates aside. "Tell me, please!"
He had her right where he wanted her. "One thing. You don't want to tell anypony about this."
"I don't? Why not? This is exactly what I'd want to tell them about."
"Not so fast." He held up a lone hoof. "If you do it now, you're just making more wild accusations without proof. Get Cadance, bring her. That will be all the proof in the world, and none of them can argue that."
He willed up a bit of parchment, a map already scrawled on it. "This will get you there."
"Why haven't you gone?" Not that she didn't bring the paper closer to herself. "If you know where she is."
"Noticing things is my specialty." Perception sat up tall. "Not spelunking. That looked way too dangerous for me, but I hear you're an adventurer. You can handle it, I bet."
Twilight looked over the map. "It starts... And... through that? Hm... This is a mildly dangerous path."
"Which you must travel twice, once with Cadance, but then everypony will know you were telling the truth." He nodded at his enemy agent. "Can you do it?"
"I have to!" She folded the paper and shoved it away in a pocket. "For Cadance's sake! For my brother's sake! Thank you." She offered a hoof towards him. "I owe you one."
Yes, she did... He knew better than to grind that in. "What are friends for?" He met her hoof with one of his own in a merry clop of union. "Good luck! Get her back."
"I will." She jumped down from her seat and dashed off to mount a rescue effort.
He chuckled softly to himself. Excellent. With her sent scurrying before the wedding, she should get back in time... But there were other steps to be taken.
"Ma'am!" Celestia nodded to the saluting guard and moved to walk past him in her stately way. "Ma'am." He put a hoof in front of her, arm with it. "We need to talk, Your Royal Highness."
The other guard gaped at him as if he had sprouted an extra head, and that head was singing a lively tune.
Celestia perked an ear at the talkative guard. "I am always available to talk, when I am not otherwise busy. Unfortunately, the plans for the wedding have been a constant distraction. Is it important?"
A testing question, Perception decided. One leaders asked, daring. Was it important enough to stop what she was already doing? "I'm afraid it is, ma'am."
She tensed. Her guards would only say that if they meant it. "Very well." She waved for the other guard to remain where they were. "This way." She brought him a short distance to a sitting room. A small table offered cookies and cakes and steaming tea, which she casually partook of as she sank to her haunches. "Now, tell me what's bothering you."
Ah, an actual queen, even if she didn't like being called that. It was nice to see one that acted the part. "Your Highness. A grave attack is being mounted against the city."
Celestia quirked an ear at him. "That's why we have the shield in place, is it not?"
"There are agents already beyond it." Not even a lie. Not even an exaggeration. He was one of them, facing her. "I can show you, ma'am, if you permit me."
"How?" She scowled, not at him specifically, but seemingly more at the situation. "Shining Armor's defenses cannot be breached."
"Unless..." He leaned forward with one of his calculating smiles. "The agents were already inside when he put it up. You Royal Highness, I ask that you not panic. The ponies should assume all is well."
"Of course...." She was looking at him with suspicion. "But how do you know this?"
"I will show you, once permitted." He brought his black arms together, metal-clad hooves clanging together. "Ma'am."
"Permission given," she stated in flat seriousness. "Show me."
So he did, green flames revealing him for a changeling, not a pony, and certainly not a guard. "Your highness."
She recoiled in surprise. "What are you?!"
She didn't already know a changeling on sight? A mark against her. "An existential threat, at least those that look like me, but not all of them." He hissclicked his tongue against his sharp teeth. "Our queen is busy making her moves, clumsily, but, given time, she will succeed, and you will fall. But I would rather--" Oops, Celestia's horn was glowing dangerously. "I am not your enemy."
"That there is any doubt is why we continue to speak." She directed a hoof at Perception. "Who are you and what are you? Speak the truth entirely!"
"There is little time for that... You are being watched. Resume your duties, but know that I am working on your behalf."
A tense moment passed, the two watching one another. She rose though. "Very well... I will at least have your name, your actual name."
"Perception Gap." He dipped his head at her low. "At your service. I am making my own moves to counter. Be ready to act, but don't look the part."
"I will continue to be a proper princess." She strode from the room with a kind smile, as if nothing of import had happened. "Poor thing," she whispered to the other guard. "He forgot his anniversary and needed a day off."
The other guard saluted sharply. "You are good to us, ma'am!" It was reason enough for Perception to trot away with the excuse given for him to leave with a sheepish expression as if he had a mare he needed to try and placate.
"Letter!" A postal pony handed him a scroll and tipped his hat. "Enjoy!" And off he flew to the next house.
Perception closed the door and willed the scroll to unfurl. This revealed the childish writing of his left-hoof 'ling.
Hello!
I did everything you said. It wasn't easy, but I did it! Some of them were really angry at me, but some of them weren't. None of them told on me.
Good. With Chrysalis running such a shoddy hive, he imagined few of them would be rushing to squeal to her.
There was one extra angry one. Pharynx. Be careful around that one. Really loyal, yelled at me for 'not having my mind on the hive'. It wasn't fun... He won't be joining us.
On the contrary, he sounded like an excellent recruit... But not for that first part, no...
I did my best! I think about ten or so loyal to us are on the mission to conquer Canterlot. I hope that's enough!
Only ten? That wasn't as many as Perception had hoped for... Still... It was at least something...
I miss you. When do we get to hang out again? Is your mission almost over?
He was loyal, but also kind of sappy. Perception smiled a little as he read those words. Treating friends right was a step he had missed in his past life. A mistake not to be repeated! He would make time for his friend as soon as he could.
A lot of the changelings are asking what you'll do for food when you're in charge. I didn't know, so I told them you had big ideas, but didn't go into it.
No specific promises, good... Just as he had instructed. He would feed his people. A tyrant that failed to feed his people was in constant danger. Only a poor one let his people's tummies rumble. What was he, Chrysalis? That she was so comically poor at meeting their basic needs was half the reason he could make the progress he had. If she was running a tight ship, things would be different.
The timeline was growing tight, but not too tight for him to pen a quick reply to his friend and ally, assuring him all was moving forward, and they would get some quality time together as soon as possible, in better circumstances ideally.
He just had to pull off the coup and not die in the process. He couldn't promise that. Few would-be tyrants could and not be lying.