The One
Twilight Sparkle pressed herself against the cold stone wall and sucked in her stomach, attempting to make herself as flat as possible through pure force of will. She was going to kill Celestia. Really, honestly, absolutely this time, for sure. Later, though—for now, she held her breath and waited.
It was a monitor lizard (and here Twilight interrupted her own train of thought to make a note to be sarcastic at Celestia about that when she got back—a monitor to monitor the door, oh yes, very clever), but this one was about thirty feet long. Her books claimed its species' vision was based on movement, so if she stayed very, very still...
Its tongue flicked out, and it stopped in its tracks. Its enormous head began to turn slowly in Twilight's direction, and it hissed. Ah. Of course. Suddenly, it seemed like time to go.
Twilight exploded into motion, and behind her, the creature's nose crashed headlong into the wall she'd just left. Her wings flared instinctively, but there was no room in the corridor to take to the air—it was barely half again as tall as she was. Still, she flapped them in an attempt to pick up a little speed.
She jumped in full stride, twisting wildly in the air to evade the thrashing hind foot of the behemoth. It caught on her catsuit, throwing her off balance and causing her to tumble to the ground in a heap. She cringed, expecting to be set upon instantly, but no teeth came. When she opened her eyes, she saw why; it was too big! It had wedged itself across the corridor while trying to turn to get at her, and appeared to be completely stuck. It was glaring bloody daggers at her, and every breath came out as a hateful hiss. She stuck her tongue out at it, smoothed out the tear in her sneaking suit, and turned up the corridor toward her goal.
***
Twilight ruffled her wings, attempting to smooth out her slightly blackened feathers. Ahead of her, the stone corridor made an abrupt, ninety-degree turn. She narrowed her eyes and glared at it. Ohhh, no. She was not going to be caught out twice. After a brief consideration, she found a small pebble, and tossed it gently into the cross-corridor with her magic.
Nothing happened. She waited, tensed to flee, or duck, or shield herself, or to wink back up the hall, but nothing stubbornly continued to happen. Finally, she followed the pebble. Twilight barely had time to register the quiet 'click' beneath her hoof before the fifty or so gallons of water spilled down out of the ceiling and onto her head.
***
Twilight was cold and tired. She was soggy, and yet also slightly burnt. Her tail had been charred at the tip, but the ludicrous spinning saw trap two rooms back had taken care of that for her—it was now several inches shorter, instead.
She swayed slightly on her hooves as she regarded the wall in front of her. The hall came to a dead end here, but it was not a bare wall. Instead, somepony (and she had a good idea who) had put up a bas relief, split into a grid, and missing one tile so that the pieces could be slid, and scrambled and unscrambled. Clearly, she was meant to unscramble the tiles, and probably that would open up the door and she could keep going. It might shoot fire or poison arrows at her while it opened, of course, but that was clearly what she was meant to do. It looked like it would make a picture of Celestia's face. Grinning.
Twilight charged up her horn.
***
Blowing up a wall had never felt so good. Twilight had stood there, breathing heavily through her nose while the rock dust settled. There had been tree sap and chicken feathers as well, but most of those had been rocketed down the corridor with the rubble of the grinning portrait. A few little tufts were stuck to her—one bunch of feathers over an ear, another covering her cutie mark on one side, a few feathers under each hoof—but she hardly noticed, and certainly didn't care. She was almost there; she could feel it. Warmth was seeping back into her bones, and she felt more lively than she had in a score of rooms as she turned a corner, and skidded to a stop.
That explained the warmth, anyway. Twilight's mouth hung open as she stared out into the enormous chamber before her. The floor dropped away immediately, plunging at least a hundred yards to a glowing, hissing, quietly bubbling cauldron of lava (magma, rather, she corrected herself) that covered the entire floor. Perhaps another hundred yards in front of her, a spire soared from the gurgling floor. It was clearly an artifact of pony hooves; it was perfectly square, and tapered gently and regularly from its base to its precisely level top, which was about another ten yards higher than the opening of the corridor. Twilight was not too tired to ask why Canterlot Castle had a magma lake deep under its foundations, but she didn't give it too much thought before giving up in a mental huff.
She eyed the top of the spire. It shouldn't be too hard to wink over to it, but she hesitated. A slight, tired, lopsided smile spread across her muzzle. This was a task for a princess, after all. So she closed her eyes, and stepped out into the void.
***
She realized she was laughing. All the stress and tension that had built up over the course of her day streamed out behind her like her mane and tail as she dove and swooped in the thermals over the lava. It was nearly effortless. The rising air carried her nearly to the ceiling in an instant, and caressed her cupped wings when she opened them to brake from a dive. She soared with glorious ease around the circumference of the vault, but the little responsible voice in her voice began to reassert itself. With reluctance, she banked toward the central spire and half-folded her wings to descend to the platform at the top.
There it was. Her goal. What Celestia, smiling, had asked her to retrieve 'from the vault'. It was a small box, cubical, about half a foot on a side. It appeared to be made of some dark and highly polished stone, but Twilight couldn't be sure what. It didn't really matter. All that mattered was that she had it, and that there were no enchantments on it to keep her from 'porting with it straight back to Celestia's study. So she did.
***
Twilight stumbled to one knee, and tried to pretend she'd done it on purpose, as a flourish while she held out the black box in her magic. Celestia and Luna both were seated before her; Luna grave, Celestia with a smile just barely tugging at the corners of her mouth. The golden glow of Celestia's magic appeared around the box, and Twilight gratefully relinquished it. She'd yell at Celestia for sending her on an unprepared dungeon crawl later—what was important now was that she'd done what had been asked of her.
Twilight's head sagged, and she watched through the fringe of her hair as Celestia passed the box to Luna with as much solemnity as she could muster (which was quite a bit, even when she was just about to burst into peals of laughter). Luna accepted it and regarded Twilight.
“Twilight Sparkle,” she proclaimed, though fortunately at an indoor sort of volume, “we wish to extend our particular congratulations on thy ascension.”
Luna's face broke into a fond smile as she continued more softly, “We would like to present thee with something that belonged to us when we were a filly. It was one of our greatest treasures, and it is something no Princess of Equestria should be without. Truly, we have found it most indispensable in many of our most important deliberations.”
Twilight sensed Luna do something to the box with her magic, presumably breaking a seal that had stood unbending for a thousand years or more. She held her breath as she accepted the chest back from Luna, and opened it.
Twilight stared into the box, then slowly looked up at Luna, who was veritably beaming back at her. Slowly, she lifted the contents of the ancient chest into view.
It was bright yellow. It was... made of rubber. It was shaped, indeed, like a cheerful little duckie, with cheerful blue eyes and a smiling orange beak. With mounting dread, Twilight squeezed it with her magic.
It squeaked.
Author's Note
Rubber Duckie, thou art the one,
Thou makest bath time double the fun!
Rubber Duckie, we are exceedingly fond of thee!
Rubber Duckie, joy of joys,
When we squeeze thee, thou makest noise!
Rubber Duckie, thou art our only friend, we see...
