Chrysalis slipped through the door, closing it behind herself, and returned her body to its natural shape. Getting inside the castle had been even easier than she'd anticipated, and once inside it had been surprisingly simple to get past all the guards and ponies she met by switching through various disguises. Now she was inside the library, where she'd been told Celestia was reading alone, and all she needed to do was take her by surprise.
She began to walk between two tall bookcases, listening for any sound that might have informed her of the alicorn's position, but she suddenly came to a stop. In front of her was a large wall of what looked like white fabric. She tried to prod the barrier with a hoof and found it was flexible but resistant, and a little sticky. She detached her hoof and moved her head closer to observe the thing, but she was distracted by a cacophony of sounds coming from behind her, like a multitude of very large legs clittering over the pavement.
She turned around and found a large spider staring back. "Hello, Chrysalis," the spider said in Celestia's voice.
Chrysalis immediately teleported out. Or, she tried to, at least. But instead of reappearing outside of the castle she found herself stuck on a web in a corner of the library. She tried to teleport away again, but the web blocked her magic.
Celestia calmly made her way to her by crawling up on a wall and then walking upside down on the ceiling. "What brings you here?" she asked to the changeling.
Chrysalis silently gulped, trembling in fear, and she stared at the large arachnid's body as it moved towards her, her face reflecting in each one of Celestia's six bulbous eyes.
The spider momentarily stopped and tilted her head to the side. "Oh, sorry," she said with a small jump, "I guess you haven't been informed about this yet. I'm a spider now."
"So... how did it happen?" Chrysalis asked, trying to stay as far from the spider as she could. Not that she could stay that much further from her, given how she was stuck on the web, but at least she tried.
"It just did," Celestia replied, going back to walking towards Chrysalis. "So, what brings you here?"
Chrysalis didn't reply. Instead, she just silently stared as the spider moved closer to her, placed herself over her body, and began to weave a web around her. She looked up to see the spider's fangs, twitching just above her face, and her body involuntarily began to shake. "Are... Are you going to t-trap me here?" she finally managed to say.
"Why do you ask, dear?" Celestia asked.
Chrysalis lowered her eyes and stared at the way the spider's legs were working on her web.
Celestia followed her gaze. "Oh, sorry, I wasn't doing that on purpose. Must be my spider instincts taking over," she said. She did not stop weaving her web.
"A-A-Are you not-t going to st-stop?" the changeling asked, frightened.
Celestia looked back at her legs. "Oh, silly me. I forgot to stop myself." She still kept going.
Chrysalis's limbs were completely blocked at that point. She gave out a sound from her throat, halfway between a grunt and a desperate cry for mercy.
Celestia looked at her legs once more. "I really need to start working on controlling my instincts." Her legs did not stop. "Although, now that I think about it, this would be an appropriate payback for what you did to me. Forced to hang from the ceiling inside a cocoon, your captor's body crawling on the outside of your prison, your powers drained from you. The dreadful wait as you observe what may happen next, knowing that, whatever it may be, it's fully outside of your control. Knowing that the thing that captured you cannot possibly have any good intentions towards you."
Chrysalis gulped.
Celestia finished covering the entirety of the changeling's body in her web. "Did you know, Chrysalis, that spiders usually eat bugs?"
Chrysalis nodded. Then, upon realizing that the spider could not see her through the web, she tried to reply. "Y-Y-Y-Yes, I-I k-k-knew ab-b-b-bout tha-at," she finally managed to get out of her dry throat.
"And do you know what they do with them before eating them?" the spider asked, repositioning herself over Chrysalis's body.
"N-N-N-No," the terrified changeling said, putting a great deal of effort into making sure that her words actually left her mouth, and that they were audible and intelligible, unlike the constant squeals of pure terror she was constantly emitting.
"First," Celestia began, "they leave their web and wait for them to fall into it. Then, once their prey is helplessly trapped, they make their way towards it and imprison it inside a cocoon of web. And then, once they have made sure that their next meal can't escape... Well..."
Chrysalis was paralysed, hyperventilating, eyes wide as she stared at the spider's shadow visible through the white walls of her prison.
Celestia repositioned herself once more. "Once they have their prey where they want it, they bite into the cocoon and inject it with their venom, melting their victim, and then they drink it out." Celestia leaned back, ready to strike.
Chrysalis's survival instincts overtook her rational mind and waked her from her state of shock. "Wait!" she screamed, "I was actually here to become your friend!" she lied.
Celestia's fangs pierced through the surface of the cocoon, barely stopping in time not to hit Chrysalis's face. The spider slowly took them out. "Uh, hem... Sorry about that. I wasn't actually planning on biting you, my instincts just sort of took over me. I really need to learn how to control them."
Chrysalis was both extremely relieved and inconceivably furious. She decided it was best to choose the calmer of the two sides when dealing with her natural predator. "Thank you for not killing me," she said.
Celestia grabbed Chrysalis's cocoon and began to drag it across the ceiling, then secured it with a thread of her web and left it to hang in the middle of the room.
"Wait! What is happening? What are you doing?" Chrysalis asked.
"I'm leaving you there. I'll decide what to do of you later, now I need to finish my book," Celestia replied.
"Hey guys! We've got another one!" a voice cheerfully said from Chrysalis's left.
Numerous other voices cheered back from a multitude of other cocoons hanging all around the one the changeling was in.
"Who are you?" Chrysalis asked.
"Mostly guards, and some members of the castle's staff. I bet Celestia did the whole trying to eat you thing to you too, right?"
Chrysalis didn't answer that. "So how long have you guys been here for?"
"Heh, a couple of days at most. Don't worry, she'll remember about us eventually. Wanna play chess in the meantime?"
"How do you even play chess withou-"
"I'll start! Knight in C three."
Chrysalis gave a low, frustrated sigh.