(OOC Note: Please send a PM to Fauna Blake and Liadán Ó Móráin if you'd like to participate in this thread! NOTE: This thread is currently locked because we're going to move it to a later date, when we're all less busy.)
As the first rays of sunlight hit the tall, white building nestled in Diagon Alley, a creature poised on the roof looked up. The upward turn of its head happened so slowly, and its eyes flashed so quickly, that it seemed like a trick of the light. The sphinx had waited there, crouched like a gargoyle, the whole night. It had watched Ra journey across the night sky, watched him escape Apophis on the Boat of Millions of years, and seen Khepri pull up the sun.
Ra had succeeded in his travels, and a new day had begun. Now it was the Sphinx's turn.
It leapt from the roof, paws landing softly on stone, wings extended slightly. The sphinx leaned against the wall of Gringotts, became the wall, until a short, stout figure unlocked the bronze front doors. Then it slipped inside, disappearing behind a column as the goblin turned and blinked, thinking he'd seen the column sprout a tail.
Once the sphinx followed the goblin into the stone passageways below, it ventured deeper, past the low-security vaults, past the standard locks and charms, until the steel tracks faded out beneath its claws and the sphinx entered one of the lowest levels. The human could bury it, disguise it, hide it in three distinct places, but the sphinx would not rest until every last bit of stolen treasure was found. It would bring the treasure back to its rightful tomb. And then it would return to punish the thief.
The human was so young, like all humans. In the vast desert of the world, she was just a grain of sand, and would be swept away by her own folly. She pretended to study the past, to look to the future, but she was blind. The sphinx had seen humans take what was not theirs for ages, grasping power in their fragile hands, holding fast until their fingers crumbled.
Humans brought ruin upon themselves. The sphinx was only the guardian, and would guard its treasure till the end of the earth.
When the sphinx reached Vault 821, it paced in front of the entrance. The treasure was there, just past its reach! The sphinx closed its eyes and concentrated. It brought forth the magic of time, remembering when this building was not here, this city was not here, and these walls and locks did not exist. It conjured forth an image so strong that the door wavered, the walls creaked, and then...
The sphinx was transported inside the vault. It tiredly lifted its head, opened its eyes. Alarm bells blared, reverberating throughout the lower level.
Something felt wrong. The sphinx tried to breathe, but the very air had turned to smoke, and the stone floor beneath its paws burned. Its movements felt sluggish and uncoordinated. The sphinx had never felt like that before.
The sphinx took flight, accidentally knocking into a portrait and an urn before touching down to the floor and shaking its head. It tried again, hovering over the piles of galleons, the family heirlooms, the crests and baubles. But it could sense the dagger, could smell it tucked away in fabric, hidden in a box, piled atop other treasures. The sphinx only wanted the one treasure. It dove for it, claws extended, ripping one plank off the wooden casing.
Suddenly, a deep rumble sounded, eyes narrowed and gleamed in the dark, and a dragon emerged from the corner of the vault, using its talons to fling the sphinx against the wall.
If the goblins hadn't heard the alarm, they certainly heard the victory roar of the dragon as it loomed over the fallen creature, and then crept back into the darkness.
As the light left the sphinx's eyes, it stretched out one bloody paw towards the treasure, now so far out of reach. It waited to turn to dust, as all sphinxes went when they perished. But there wasn't enough magic left in the sphinx to allow it, and the body remained.