There’s a Changeling under my bed.
Preposterous.
The chill of the night creeped under my blankets. Somewhere, I can hear the warped sound of the magical barrier outside. I hope Shining isn’t too tired.
It’s awfully hot in here. I’d open the window, but what if one flies in? I cast a nervous glance outside, towards the stars.
There’s a Changeling outside.
I know they’re out there, hiding in the bushes, stalking behind the tall blades of grass. I turned over and buried my face in my hooves. Why didn’t I ask Spike to mow the lawn before we left? I suddenly sit up in horror, drops of sweat running down my body and dripping off my bangs.
There’s a Changeling in his basket.
Snoozing softly, its chest rose and fell, as if it were balancing a small feather. I stared in frozen shock and watched as its wings twitched subconsciously during slumber. If I move, it’ll strike. If I don’t move it’ll strike. I closed my eyes and swallowed. This can’t be happening. It can’t…
Wait. That’s not a Changeling. It’s Spike. My Spike. Spike is okay. I fell back in bed and threw a hoof to my head. What’s wrong with me? Here I am, getting myself all worked up and cowering under my blankets like a little filly. The Wedding was two nights ago and I slept like a foal. Why am I acting like one tonight?
Maybe a glass of milk will help.
I gently slipped out of bed and tiptoed around Spike’s basket, double checking if it was really him. Halfway across the room, I stop.
The library is darker than usual. I can barely see a thing. Before I can move, I see Cadence’s reflection bouncing off the crystal walls. Her cold, unforgiving gaze grips my soul like a vice and the piercing shriek of her cruel laughter chills me to the bone. It's...too unbearable.
There’s a Changeling in the bookshelves.
Maybe milk isn’t such a good idea after all. I backtracked next to Spike’s basket, but I couldn’t take my eyes off the darkness. I’d go talk to Shining, but how can I, when I’ve been kicked out of the Wedding all together? I slowly rubbed the side of my cheek, and realized that it was wet.
The floor creaked and I gasped.
No.
Nononono. I locked all the doors. I checked and double checked. I broke into cold sweat when I peered down and saw that the window downstairs was open. Why is it open? I never leave my windows open at night, except when I’m expecting Owlicious, and...and he already flew in for the night. Didn't he?
My breathing grew shaky as I descended down the stairs. I lit up my horn as my feeling of terror intensified. I took a quick look around before closing the window and locking it up tightly. I exhaled in relief, and briefly decided to triple check all of the doors and windows. Even after quadruple checking the front door, I can't shake the feeling that her shadow will darken it. The feeling of paranoia is so intoxicating, I could almost choke on it. Without a moment's hesitation, I make another round.
Foalish as it was, we can never be too careful. I’m sure Fluttershy would agree with me. Sweet, gentle Fluttershy.
Suddenly, the thought of my friends crossed my mind. My sisters, my family. As I gazed outside once more, I rested my hoof against the glass. Sugarcube Corner was the closest to the Library. Pinkie wouldn’t mind a visitor at this hour, would she?
After a moment's pause, I smiled and shook my head. Of course she wouldn’t. She’s Pinkie.
Is she though?
My mind is suddenly plagued by the thought of a Changeling replacing her, and is sleeping in her bed, right now, this very minute.
Now I have the urge to visit all my friends, just to see if they’re alright. Is Rainbow safe and sound in her cloud palace? Is Rarity really back at the Boutique, working on a new dress? Did we accidently leave the right Applejack back in Canterlot?
My mind spirals, and I can’t seem to breathe. No...no, not that...Anything but that... If...If something happened to my friends, I’d never forgive myself. Their air of confidence, their warming smiles, gone in an instant. Never to be seen or heard from again.
The clock ticks on the wall.
I need to get ahold of myself.
Sleep, that’s what I need. I forced a silent laugh as I made my way back upstairs. One day of excitement, and I’m already all skiddly-boppy-boo. We’ve faced worse before...I halt at the top of the stairs.
Except we haven’t.
I’m starting to think that I should pull an all-nighter instead. But I know I need rest.
If Rainbow Dash were here, she’d tell me to pony up and get to bed. Maybe Cadence would tuck me in like she used to...and maybe read me a story...
I’m scared.
I brought myself back to the window and caught my reflection. It’s a sight that I’m well accustomed to. Messy bed head, accompanied by dark circles under my eyes.
It’s barely been six months and I’ve already helped fight Nightmare Moon, Discord, and now...I don’t want to think about it. Sometimes I ask myself...what the hay did I get myself into? Ever since we became one with the elements...nothing’s been quite the same anymore.
Gone is the average mare living in a nice little town with a small group of nice little friends. And something tells me this time of peace won’t last. I know it won't last, and I'm terrified. Maybe they’ll return, maybe not. The Princess insists that our battle is over, but... I can’t help myself.
Just because we can’t see them doesn’t mean they’re not there.
I drew myself to full height. Yet... my family...needs me.
Something buzzes under my bed.
I decide to ignore it.
No matter what I'm feeling...I cant let them down. Not when I have my strength left.
“...Twilight?”
I almost jump out of my skin. “Sorry I scared you,” Spike apologized, sitting up and rubbing his eyes. “What’re you doing up so late?”
I smile as I climb into bed. “Just had a glass of milk, that’s all. Go back to sleep, Spike.”
In his tired state, Spike only nodded and sunk back into the comfort of his pillow. “Mkay. G’night, Twi.”
“...Spike?”
“Hmmm?”
“I love you.”
Spike lifted his head, looking pleasantly surprised. “Love you too, Twilight. Night.”
With a soft smile, I rested my head on my own pillow and closed my eyes, paying no mind to the Changeling snoozing under my bed.
Author's Note
This is something I wanted to experiment with. The events of the Canterlot Wedding were hard on everyone, so I decided to make a little something tonight. I'm no stranger to jumping at everything that moves in the night 
I'd like to think that the fear is still there in the back of her mind, but no matter what, she can still conquer it. If there are any mistakes, please let me know. 
