It was the dusk of a cold Sunday evening. A young mare had just left visiting her parents' home in Canterlot. She was walking through the city towards the Royal Palace. She was already late getting back to Celestia's School for Gifted Unicorns. She tugged at the brim of her velvet chapeau to shield her eyes from the setting sun. She wasn't really a fan of hats. But her mother had made it for her, and she had been insistent that she wear it to show the princess. It didn't hurt that it also kept the cold winter wind off of her.

As the sun slipped below the horizon, dusk gave way to twilight. The unicorn of the same name stopped and stood on a street corner and waited. It would be the vernal equinox next week, the first day of spring. But as she stood there, she could still feel the icy grip that winter had on the mountain-side city. The red and orange hues of the sky looked deceptively warm from the inside of a house window. The colors refracted off of the frost on the sidewalks. Its slippery presence was a more accurate indication of the present climate.

She stood there and listened. The city was rarely quiet. She could hear the distant bustle of carts moving around in the commercial district. She could smell the wood smoke emanating from the chimneys in the neighborhood. She waited, and watched the fog of her warm breath swirl in front of her.

"And here... we... go," Twilight whispered to herself. The street lights flickered to life as the moon crested the horizon. The young pony looked up at the moon. The Mare in the Moon looked back at her. She resumed her walk along the main street. She cut down a dark alleyway. It was a shortcut that she'd learned. She had long-ago mapped out the most efficient route to take back to the castle after visiting her parents for the weekend. It wasn't the most scenic of routes, but she was nothing if not pragmatic. And unfortunately, she was also a predictable creature of habit.

"Well, well. What do we have here?" she heard a voice from the shadows ahead of her.

"Looks like somepony is lost," came another voice beside her.

"All alone in the city night," came a third behind her, cutting off her escape.

"I'm not lost!" Twilight said defensively. "I'm heading back to Canterlot Castle. I'm Celestia's student!"

The three gruff stallions surrounded her, slowly closing in.

"What's in the bag there, Sweetie?" one asked.

"Bits, I'd wager!" another said as the third grabbed her saddlebag, tearing the strap.

"Hey!" Twilight shouted.

"Nah, it's just books!" he said as he rifled through her bag.

"Forget 'em then! Get the rope. I bet the princess will pay a nice ransom to get her little pony back." The other stallion pulled out a coil of rope and advanced on her.

"Stupid books!" the other complained, throwing her bag to the ground, spilling the books out into a muddy puddle, soiling the pages. The corner of Twilight's eye twitched.

"Oh, Sugar," Twilight's shaky voice rasped as her horn burned a hole through the hat, "you've just gone and done the dumbest thing in your whole life."

By the time the Royal Guards responded to the noise reports of "Armageddon" happening, all they found were three bloodied, bruised, and unconscious stallions roped up and hung by their hooves from the street light like discarded horseshoes. Each of them had a scorched word burned into their singed fur.

The rope running from their tied hooves, over the pole and to the other ponies were woven into an intricate pattern, resembling a rectangular spiderweb.

"What do you make of it, Sergeant?" one of the guards asked. The sergeant stepped closer and she inspected the pattern.

"It almost looks like a..."

"Twilight! My most faithful student!" Princess Celestia greeted the young pony.

"Princess," Twilight responded with a small bow. It wasn't the deep bow of somepony meeting the princess for the first time. It was a small gesture bore of familiar habit, but also respect.

"Twilight, how many times must I tell you to just call me 'Celestia'," she said.

"At least one more time, Princess," Twilight said with just the subtlest of nods. Twilight had been attending Celestia's School for Gifted Unicorns ever since she was a small filly. Twilight had been a star student ever since she had arrived. The princess herself had taken Twilight under her wing as her personal protege. The white princess towered over the young pony even without the added height of her horn. And her broad wingspan all but dwarfed any other pony she met. It was intimidating to anypony that did not know her true, kind nature. Her voice was soft, warm, and comforting. And maternal.

"Come," Celestia directed her, "I've something I want to show you in my garden." Twilight followed the princess, giving a wide berth to her ethereal, flowing mane and tail. As they walked past the entrance to the Canterlot Garden, the sunlight refracted through her translucent mane, causing it to project shimmering pastel colors onto the swirled, marble floor. Twilight's expression became quizzical as they passed the entrance to the Canterlot Garden.

"Princess, we've passed the garden," Twilight said. Celestia wore a soft, knowing smile as she looked to her student.

"I did not mean the Canterlot Garden," she said as they continued toward the castle's west wing. "I mean my personal garden." Twilight could not stifle her gasp. She had only ever heard whispers of Celestia's private garden. Her mother used to tell her stories about it when she was just a foal. It was rumored to have the rarest, most exotic flora in all of Equestria. The other students at Celestia's school gossiped that it was to have the most potent herbs in the land for 'recreational use'. But Twilight paid such deplorable talk no heed. No theories were to be believed, after all. It was Celestia's private sanctuary. Nopony was allowed in Celestia's personal garden except the princess herself.

Until now.

"P-Princess! This is- it's such an honor! I- I don't know what to say!" Twilight stuttered. "Thank you!" Princess Celestia led her into the hallway past her royal chambers. Castle guards flanked each of the doorways, still as statues, eyes forward. At the end of the hall was a lone doorway that was left unguarded. It was ornate, but it had no handle, or and visible means of opening, save for a round hole in the center.

Celestia bowed her head, and placed her horn into the hole. She unlocked the door with a spell that only she could cast. The gold relief etching of the door glowed to life. A seam materialized up the middle of the door and it split open on its own. Bright sunlight filled the hallway as the door opened. Twilight squinted and followed Celestia through the doorway, stepping outside into her garden.

Twilight had expected Celestia's private garden to be many things. She expected a jungle of exotic plants. She expected a vast collection of carefully labeled nature exhibits like the botanical garden in the Canterlot Conservatory. She expected a simple, yet perfectly-manicured vegetable garden, like her own mother's.

They walked through the doorway, into a jarring transition from the marble tile of the castle to a course cobblestone pathway leading to a solitary tree amid a sea of rather plain field grass.

As soon as they both were through, the door closed behind them. Twilight looked back at the exterior of the castle. There was no visible sign of a door having existed in the wall at all. Her eyes traveled upwards along the ancient architecture to one of the spires. Twilight recognized the tower with her guest dormitory in it. She orientated herself within her mental map of the castle. She'd been in that very window up there. She'd looked out at the very ground that they were standing on. But it did not look like this. She'd never seen this stone path or tree before in her life. Twilight's mind struggled with the geographic dissonance.

"I- I know where we are... but... where are we?" Twilight asked.

"This is the West Castle Courtyard," Celestia said.

"I know but-" Twilight spun around in place, still trying to get her bearings. "But this isn't here," she said, pointing at the tree. "There are supposed to be some flowering bushes and... a couple of benches and-" Twilight noticed how warm she was. How green the grass was. It was the last frost of winter not more than a week earlier. But it felt like the height of a balmy summer day where they stood. "How?" Celestia gave her the same smile she always had when she would impart her knowledge upon her students.

"We are in the West Castle Courtyard. And we are not," Celestia began to explain. "This... place, exists in the same space, in the same time, but layered, superimposed on top of what is already there. Like pages in a book."

"I don't understand," Twilight said.

"It's like a pocket, or a bubble in the world. Like a bubble in water. The world is like the sea. Even if there is a bubble in it, the sea is still the sea, The water moves around it as though it were not even there. So too, does the bubble exist, without regard for the water around it. But this is a bubble of space, of reality, of my design. Technically, it does not exist. It is unable to be measured, observed, or reached from the outside but by my spell to access it. Without it, that door leads nowhere." Twilight followed her gaze to the bare wall where the door had been.

"This is... unbelievable!" Twilight said. Celestia place her hoof on Twilight's shoulder.

"Twilight, my dear. Please give yourself more credit," Celestia said. "You can't even imagine... what you can not imagine." Twilight gave her a strange look. She assumed it was just one of those cryptic things that Celestia would say from time to time that probably had a much deeper meaning than she would be able to handle in the moment. Twilight found that it was best to not think about such things too much. She needn't wait long. "Never underestimate what you are capable of believing. What other evidence do you need beyond what your very own eyes report?"

"What if I could be under the effects of a perception-altering potion, or spell? What if I could be dreaming? What if-" Celestia cut off Twilight with her hoof.

"Did you know that 'if' is the middle word of 'life'?" Celestia asked. She moved her hoof away from Twilight's lips and walked toward the tree. "This is what I brought you here to see."

"A tree?" Twilight asked dubiously.

"Yes," Celestia answered rather plainly. "Do you think that you might be able to identify it?" Twilight smiled. It was an academic question. Twilight's favorite kind. She walked closer to the tree, inspecting it intently. It was massive. The gnarled limbs looked ancient. The leaves looked... unlike like leaves of a deciduous tree. But it wasn't the needles of a coniferous tree. It almost looked like bits of moss on the tips of the branches. She ran her hoof over the bark. Everything about it looked alien. She'd never seen anything like it before in her life. Not in person, or in any of her textbooks.

"I- I have no idea what kind of tree this is," Twilight admitted.

"You do," Celestia assured her. "Here, let me give you a hint." Celestia took a small branch in her magic and gave it a gentle snap. She picked up a small pot of dirt that was sitting at the tree's base. She placed the small branch into the dirt and gave the pot to Twilight. Her eyes lit up. She recognized it immediately.

"It's a Bonsai Tree!" she said, looking at the tiny pot in her hooves. "My mother has one like this."

"I know," Celestia said. "I gave it to her." Twilight regained her composure. Her eyes move up along the size of the massive tree looming over them.

"It's a giant Bonsai Tree," Twilight gasped. "But the largest one I've ever seen was at the Conservatory. And that was only-" Twilight made a motion with her hoof, barely at her waist in height. She stared at the massive tree. "How? I mean this tree must be... for it it have grown so large, it would have taken-"

"Time, Twilight," Celestia answered. "Time, care, and patience. All things that I have in abundance."

"Wow," Twilight breathed, still in awe of the living miracle of nature.

"The farm pony that plants a date tree, never reaps the dates from it," Celestia said. "It takes longer than the lifespan of a pony for a date tree to reach fruit-bearing maturity. And yet, date trees orchards exist. Planted by ponies who knew that they themselves would never reap the fruits of their labor. These ponies understood the value of planning for the future." Celestia walked in a slow circle around the thick trunk of the massive tree, running the tip of her wing along the familiar grain of the bark.

"I've spent all of my life caring for this tree. Each limb that you see, every single branch, was once a choice that I had to make at some point in time. Keep this branch, or prune it? All of those choices would not reveal their results for many years. Every choice had lasting effects, shaping the tree that you see today." Celestia regarded her pupil as she looked at her tree. "Perhaps, one day, I will tell you the story of when I planted the seed for this tree."

"I would love to hear it," Twilight said.

"A tale for another time, I'm afraid. For now, there is something else we must attend to," Celestia said.

"Okay," Twilight resigned, setting the pot down to leave on the ground. Celestia lifted it back into her hooves.

"No, Twilight. This one is yours. Keep it."

"Thank you, Princess."

"You're very welcome. Now come." Twilight followed Celestia toward the castle wall. Her horn glowed and the invisible seams in the wall opened. Back inside the castle, they were met with the brisk air of Equestria still just emerging from a cold winter. Twilight walked back to her chambers in the castle as Celestia escorted her. Inside, Twilight set the tiny tree spout on her desk.

"Celestia, I promise I'll take care of this!" Twilight promised. "My mother always doted on her tiny tree. I never knew why she loved it so much. But I do now." Celestia smiled.

"Come. I have a surprise for you." Twilight looked at the small tree on her desk.

"It's not the tree?"

"I mean, another surprise," Celestia opened the door and led them back out into the hallway. "It's something that I've been putting off for far too long. But I can't wait any longer. Especially after that little incident in the city where you were accosted by those thugs."

"It was nothing I couldn't handle," Twilight said. "They tried to mug the wrong unicorn."

"Yes, Twilight, you did well. I'm glad that you were paying attention during those defensive magic courses. But I just can't bear the thought of-" Celestia cut herself off, refusing to even speak of the unmentionable. They stopped outside of the Royal Guard barracks. The Commander received her and gave a sharp salute. Celestia nodded and he turned to go inside. "I have every confidence in your abilities, Twilight. This isn't for you. It's for me. For my peace of mind," Celestia said

"What is?" Twilight asked.

"Your Highness!" a Royal Guard pony emerged from the barracks and presented himself before the princess. He bowed quickly before he stood at attention and gave a firm salute. "Reporting as ordered!"

"Twilight," Celestia said, "I am assigning you your own personal guard pony. He will be at your complete command. He will obey your will as though your words were my very own. And he will defend you with his life."

"YES MA'AM!" the guard pony confirmed.

"Twilight, may I present Lieutenant Night Light," Celestia introduced. "Lieutenant, I would like you to meet my most faithful student, Twilight Velvet."