Twilight Sparkle was in her library, which was not strange.
But she was not immersed in a book, which was unheard of.
It was a little past midnight, known half-seriously as “the magic hour”. Many unicorns believed that magic was at its strongest at this time. Those practicing a difficult spell would often save their efforts for when Luna's light was suspended high in the sky. Corroborating evidence that magical ability increased during “the magic hour” was lacking, but the belief persisted even among older and more skilled unicorns.
Twilight Sparkle herself was dubious of the rumored “magic hour”. Just for this particular night, she suspended her own skepticism. For the spell she was attempting, she required every bit of magical power at her disposal. Taking direction from several old legends, she had turned off all the lights in the library and illuminated the room with candles. She had also opened several spellbooks around her, another precaution advised by ancient stories told by unicornfolk. She was now sitting in this dimly-lit room with her eyes closed. She allowed the silence and calmness to fill her, taking her to a place of serenity within her own mind. She was channeling magic, more magic than she had ever channeled during even her most desperate and dangerous exploits.
Without preamble, the quiet shattered into a thousand pieces.
Startled, the purple alicorn opened her eyes. The disturbance was so abrupt and unexpected that she at first thought the world itself had exploded around her. Her gaze sweeping the immediate vicinity for the source, she half-expected to find a gaping hole where one of the walls had been. But instead of destruction, her eyes came to rest on a young dragon standing in the shadows.
Spike's features were draped with shadows and barely visible in the darkness. He appeared to be holding a round item of some sort in his hands. When he spoke, it was with a voice that hinted he had swallowed something a few seconds previous.
“Um...hi, Twi?” he uttered nervously.
Concentration was out of the question for the time being. Twilight stood up, wearing the severe, motherly look she reserved for Spike. The effect was almost spoiled by the fact that her features could barely be seen in the meager light. Fortunately, the presence of a horn and wings, both outlined in the semi-blackness, boosted her air of power. She had noticed within days of receiving them that other ponies seemed to sense her enhanced authority before they even glimpsed the wings and horn.
The lights sprang to life and the candles extinguished themselves.
“Why are you awake at this time of night?” Twilight demanded sternly.
With the regular lights illuminating the area, she noticed that the round object in his hands was a tub of ice cream. She deduced that he had vacated his bed for one of his late-night ice cream binges. She highly objected to this habit of his, but she had been doomed from the moment her number one assistant discovered he could melt the lock on the fridge.
“Um...what are you doing awake?” Spike responded hastily.
Twilight appeared to be on the verge of a lecture, but she swallowed her words. Normally she would have seized the ice cream tube, given him an austere talking-to, and dragged him back to bed by his ear. Fortunately for the young dragon, she was quite eager to talk about what she was doing. If all went as planned, she would be demonstrating something monumental to the other princesses. It was fitting that Spike would be the first to hear of it.
“I'm practicing a new kind of teleportation spell,” she explained with the ghost of a proud smile.
The young dragon was confused by her explanation.
“But you can already teleport,” he reminded her. “It's one of the first spells you learned.”
Twilight was rather touched that Spike remembered such a thing. He had been scarcely older than a newborn when she mastered that rare spell. She hadn't been aware that his memory went back that far. Rather than praise him on his excellent recollection skills, she rushed to further explain her actions.
“Yes, Spike, but this is an entirely new kind of teleportation that no unicorn has ever mastered! Aren't you curious about what others worlds are like? Haven't you ever stared at the night sky and pondered on the infinite possibilities of other universes? If I can perfect this spell, I'll be able to travel freely through all of them!”
If she expected immense awe, she was disappointed by her companion's reaction.
Spike was silent, pondering what he had been told. While he was not experienced in spellcasting beyond what he had observed, he doubted that such a complicated spell was worth mastering or even attempting. The dangers of it seemed to far outweigh the rewards. He knew the threats that existed in their own universe, from the timberwolves to more powerful enemies such as Queen Chrysalis. If Twilight was able to freely walk between worlds, it was impossible to predict what enemies she would encounter and if she would be able to defeat them. Spike's fear of losing his mother/sister figure intensified as he imagined the horrors she could be forced into a confrontation with when she utilized this new spell of hers. Not to mention he was already being tormented by what would occur if the spell went wrong and she ended up trapped in an unfamiliar place with no means of escape.
A worried Spike summed up his concerns with a single question.
“Is that....a good idea?”
Twilight was insulted that he would ask a query of that nature. Although it was egotistical of her, she prided herself on being accurate at least ninety percent of the time. If Princess Celestia, one of the most powerful beings in Equestria, trusted her with alicorn magic, it was obvious that she knew when using it was “a good idea”.
“Yes, Spike, it is,” she replied haughtily. “Isn't it past your bedtime?”
He resented being spoken to as if he were an average little child, but the sleepy dragon did not complain or protest. He ascended the stairs to the second floor, sparing his friend a perturbed glance over his shoulder. He wished to tell her that she was making a grave error by attempting this particular piece of magic, but he had no logical argument against anything she was doing. He only had worries that would most likely not stop her if she was determined.
Spike suffered a sleepless night.
It was the first of many.
With Spike safely upstairs, Twilight returned to her mission.
She turned off the lights, restored the illumination of the candles, and sat on the library floor again. She closed her eyes, attempting to block out everything that had annoyed her in the past ten minutes. Channeling her magic, she focused solely on that feeling of peace. She let the renewed silence, the renewed serenity, fill her once again.
Moments passed. Hours, perhaps. Time was nothing to an alicorn in deep concentration. Her mind had lifted her outside of time and space.
Twilight felt a tiny bubble, a minuscule sphere of warmth and light, expanding within her body. The magic inside of her was forcing itself into this sphere as it expanded. She felt it struggle, as if it was a living creature trying to burst through her stomach and chest. But she grasped it with her mind and compelled it to remain in its place. The warmth inside of her intensified as the sphere grew at an even hastier pace. It wanted to devour her from the inside, but she could not permit it to do so. With great effort that only the Element of Magic could summon, she tightened her grip on the spell. Her hooves, her ears, her horn, and her tail tingled with its power.
As if a sudden breeze had entered the room, the candles extinguished once again
In the darkness, Twilight Sparkle opened her eyes at last. A ripple of electricity darted through her body, driving a gasp of surprise from her mouth.
And then, in a flash of light that briefly illuminated the room, Twilight Sparkle disappeared.
The world was twisting and lurching.
Twilight Sparkle was falling, then she was flying, then she was on solid ground, then she was standing on water, then she was sailing through a sky that felt like an ocean. These alterations happened with such speed that she felt as if she was being thrown through an endless cycle of worlds. She saw brief glimpses of sky, ocean, sand, and landscapes that seemed to be made of nothing. And throughout this her body twisted and lurched even worse than everything around her. It was not painful, but it was not pleasant.
Finally, after minutes or hours, the world became still. The forever shifting backdrop settled into a shimmer of dark sapphire and pale ribbons of white. Pallid impressions of stars studded this unfamiliar place. It was an imitation of the night sky, except more beautiful than the night sky had ever been.
Floating in this place, Twilight was reminded of the celestial plain she had visited when she became an alicorn. With a jolt, she recalled that her transformation had only occurred a month or two ago. Many things had happened in that relatively short time that made it seem that it had been a year ago.
Is this another celestial plane? she wondered. Did I pass another test?
The idea pleased her, but it did not seem likely. If she had indeed passed another one of Princess Celestia's concealed tests, what would happen to her? One couldn't progress higher than an alicorn. Perhaps she was going to grow another pair of wings and another horn?
Twilight was thinking over that unpleasant idea when she heard voices.
“Tia, come play with me!”
“I'm working on a spell, Lulu. Play with those dolls I made you.”
The voices sounded vaguely familiar to Twilight. Yet she could not attach them to any mare or stallion she had met in her life. For that matter, she was confused as to where they were coming from. Had she indeed teleported herself to a new universe inhabited by sentient beings? But when she glanced around, she saw only a blank landscape of shimmering colors and stars.
“Big sister, must I eat this filth?”
“Lulu, it's good for you. You'll never master your magic if you're still a weedy little thing when you're my age. Don't you want to become big and strong like me?”
A sharp intake of breath from the purple alicorn. She could now identify the owners of the voices, although they sounded a bit younger. She had heard them many times before. If she was not mistaken, it was...
“Princess Celestia?” she called hopefully. “Princess Luna?”
No answer came back to her. Yet the disembodied voices of the sisters, younger than she had ever heard them in real life, rang out clearly. It was as if she was hearing echoes of them that had traveled over distant time frames.
Then a thought, an impossible yet possible thought, sprouted in her mind.
Is this Princess Luna's....mind?
That would account for the gorgeous imitation of the night sky. It would explain the disembodied voices of the princesses. If this was Princess Luna's mind, the voices were simply reverberations of memories. Exchanges between Princess Luna and her sister “Tia” that she vaguely remembered from a time far in the past.
But that's impossible! Twilight told herself, bemused. How can I be inside somepony's mind?
Yet, as impossible as it was, all the pieces fit into place of their own accord. She could not explain how the spell had resulted in her being in this place, but she had no alternate explanation. Somehow, whether it was rational or not, she has accidentally teleported into the mind of the famed Princess of the Night.
And she had no clue how to escape.