I knelt on the cold stone, the knees of my trousers dampening instantly.

I shoved the iron shelf aside, the metal scraping loudly against the walls.

Beneath it lay a brass plate set directly into the stone, green with age.

In the center of the plate was a rotary dial, cold and stiff to the touch.

I gripped the brass dial with my thumb and forefinger.

I turned it slowly to forty-two, feeling the heavy tumbler click deep inside the stone.

I reversed the turn, stopping at eleven.

My fingers were slick with sweat, making it hard to grip the metal.

I made the final turn to seventy-six.

A sharp, metallic pop echoed through the small space.

The limestone slab shifted upward by an inch.

I wedged my fingers beneath the edge of the stone and hoisted it back.

The slab was incredibly heavy, scraping against the surrounding floor as it tipped over.

A gust of freezing, musty air rushed up from the opening, smelling of damp earth and old paper.

A narrow set of stone steps descended into the blackness below.