“Angela?” I whisper. My stomach tenses in sharp cramps, but I creep forward, hands out. The ground slopes downward as the three feet of light from the main walkway slivers to black. Seb said the catacombs were more than two hundred miles long. Chill, undisturbed air engulfs me, and I stumble to my knees, hands balled by instinct. I scramble upright, anticipating a sneak attack from a monster while my eyes adjust. One click of my pocket flashlight reveals the cavernous space and its secrets. Someone has been here before. Many people.

A projection screen stands before dozens of empty chairs. A full bar is set up against the far end of the makeshift movie theater, fashioned out of a tall table and three bar stools. The dome I’m standing in reaches at least fifty feet across and another thirty high. A carton contains old-fashioned film reels in the corner, next to a sleek, portable projector, something you might see on your favorite electronics website, and a vintage cinema projector, the kind with two rotating wheels balancing a wide base. Nothing about the space looks official. How many secrets do the catacombs hold? How much activity has gone unseen by the authorities?

A shiver traces my spine as I tiptoe back to Chang. She remains in the hall, her arms folded. “I think we should go,” she says.

“Look, Chang. I really appreciate you getting me here, but you can leave now that we’re on the official tour path. I should be able to find my way out.” I adopt a confident expression and ignore the patterns in the bones behind her.

“No, you won’t. The catacombs won’t open for hours today. It’s Saturday. You need another exit from here; the main one is back under the river and locked until ten.”

Angela, Angela, Angela. My mantra plays on loop while I search for some sign of my sister and try to employ the twin powers, the psychic GPS or whatever, she swore by. Chang steps backward, watching me. “Are you feeling okay?”

A motif of femurs in a bowl shape, sunk into the tunnel’s dirt floor, lies at the bend in the path. Something about it seems familiar; I’ve seen it before, in her research photos. Angela. I visualize a thousand tiny cables extending from my frame, reaching with a million follicles, alert and ready to transmit silent messages, less of words than of yearning. I orient the directions of the compass in my mind. East-facing pathways are nonexistent—until I spy an opening in one wall at knee level, just large enough for an adult body to squeeze through.