Tap tap tap.
Celestia froze. No, nopony was behind her, she thought to herself. It's just the night. You've never felt comfortable in the night. The goddess sighed and hung her head, her mane flowing smoothly behind her. Though this time, the color seemed drained and not as brilliant as it usually looks in the sunlight. She wasn't usually out in the castle at night. Then again, she never was out at night.
She always (except now, of course) had slept trough the night with an uneasy peace, but now that Luna was back, everything was better now, right?
Right, she thought, a bit more confident this time. Luna could watch over the night that she rightfully deserved. Celestia could now rest easy, knowing her dear sister was up protecting her.
Then why did she feel so uneasy? Celestia bit her bottom lip and gazed up at her beautifully crafted stained glass windows that shone with a beautiful, deep blue tint. She gazed up at the window that had the story of the defeat of Sombra carved elegantly into it. Bright blues clashed against deep, angry reds and was surrounded by blacks and dark purples.
The memory of it made her shivver. After that short-lived war, Luna had been so different, Celestia had noticed right away. Sombra may have been sealed away in the cold, hard polar ice...
...but his words echoed in Luna's head until-
No, Celestia closed her eyes and gritted her teeth. No, she would not dwell on the past thousand years. Celestia let her hair droop in front of her eyes, her head sagging down to her hooves. One thousand cursed years of solitude had made Celestia jumpy and paranoid. Before the Nightmare Moon business, Celestia had never been afraid of monsters or creatures that would slink and scurry through the dark, but after the Nightmare, Celestia had barley felt safe in her own castle. She sighed, lifting her head back up to face the window.
She turned around and walked slowly down the red carpet, still stiff and uneasy from the darkness that surrounded her that seemed to swirl and creep around her, jeering at her foalish fears. She set out to find a more cheerful window. Perhaps Twilight's window would remind her of better times other than-
Celestia choked back a scream. Twilight's window was there in all of it's glory, but the window had... changed. Twilight's eyes were no longer closed, they were open, and staring directly at the white mare with a red gaze. Celestia backed up so she was up against the opposite wall. Twilight's unusual red eyes glared in to Celestia's blue ones, menacing and cold.
"But..." she felt her flank push up against the freezing brick of the caslte wall. She jerked her head up to look at the window behind her. Instead of Twilight and her six friends defeating Nightmare Moon, each pony was upside down and crying, the black pony with the night as her mane standing over them victoriously. Celestia reared and galloped down the halway.
No, every window had changed... Discord was holding Luna and Celestia by their tails, Sombra was holding the crystal heart, Nightmare Moon holding equestria in eternal night...
What had happened to her precious windows? Celestia slowled down to a trot, then stood completely still. She gazed back up at Twilight's window.
Then she noticed what, no, who Twilight was standing over.
Celestia herself was beneath Twilight, her glory and regal stature diminished beneath the younger allicorn. Celestia froze. Was this the window of a coup? Was this the window of her defeat?
She slowly walked towards the corrupted window, her steps echoing throughout the empty and dark hallway. Her mouth hung open in paralysing shock and her brain throbbed with a maddening numbness.
Her breath quickened and her vision began to fog and blacken. She shook her head and stopped approaching the window.
Suddenly, Twilight in the window unfolded her wings and pointed at her. Celestia screamed and jumped back away from the window. The stained glass Twilight smiled, rows of glass teeth glittering in the ominous moonlight. An eerie laugh echoed throughout the hallway and the tapping came back.
Tap tap tap.
Celestia spun around to face the window of Nightmare Moon. The colored glass nightmare that was once her sister was tapping on the window it was trapped in, a crude smile on her face.
The darkness continued to creep aound the princess.
Tap tap tap.