She shivered. Not Black Door. Not on a white day. Wains instead. Then Tenners. Even Throughbottom. This was not a key for Black Door. No.

Auri hurried through Rubric, turning left twice and right twice for balance, making sure to never follow any of the pipes too far lest she offend. Next came Greely with its twisting ways and its sulfurant smell. She got a little lost there among the crumbling walls, but eventually made her right way to Crumbledon, a narrow dirt tunnel so steep it was little more than a hole. Auri scampered down on a long ladder made of lashed-together sticks.

The bottom of the ladder dropped into a tiny, tidy room of finished stone. It was no bigger than a closet, empty except for an old oak door all bound in brass. Auri brushed off her hands, swung the door open, and stepped lightly into Wains.

The hallway was wide enough to drive a wagon through. High-ceilinged and long enough that Foxen’s light could barely reach the tangle of debris that blocked the far end. Above her, blue-white light scattered off a crystal chandelier.

Dark wood paneling hugged the lower portion of the walls, but above that was ornate plasterwork. There were broad frescoes decorating the ceiling. Women in gauze lounged about, whispering and rubbing oil on each other. Men frolicked about in the water, flapping around ridiculously in their absolute altogether.

Auri took a moment to look at the pictures as she always did, grinning wickedly. She shifted her weight from side to side, the polished marble floor chill beneath her tiny feet.

Both ends of Wains were blocked by fallen rock and earth, but in the middle it was clean as a crucible. Everything dry and tight as you please. No damp. No mold. No drafts to bring in dust. Altogether men or no, it was a seemly place, so Auri was careful to comport herself with full decorum.

There were twelve oak doors lining the hall. All fine and tight and bound in brass. Over her long years in the Underthing, Auri had opened three of them.

She walked down the hall, Foxen glowing brightly in her upheld hand. After a dozen steps, a glimmer on the marble floor caught her eye. Skipping close, she saw a crystal had fallen from the chandelier to lay unbroken on the floor. It was a lucky thing, and brave. She picked it up and put it in the pocket that didn’t have the key inside. They would only fuss if they were put together.

It wasn’t the third door, or the seventh. Auri was already planning her route down to Throughbottom when she spied the ninth door. It was waiting. Eager. The latch turned and the door eased smoothly open on silent hinges.