Once I make the mistake of looking up and see men and women clambering on our trail, the light from the lobby long gone from view, and the realization that we’re essentially trapped underground slams into me—that I can’t push through those bodies to get up and out, that I must pass through the catacombs, all the way to the other side, to exit. That, according to Valentin, there may be a serial killer out there, hunting down Angela and maybe me by mistake, and I’ve cornered myself five stories below the surface. Panic claws at my chest, as if it were a literal zombie risen from its marshy tomb below. What the hell was I thinking, agreeing to visit this place when I can barely stand the claustrophobia of the subway and someone could follow me down here and attack at close quarters? When Seb taps me from above and asks if I’m okay, I realize I’ve been muttering shit shit shit on a loop.

Finally, when we reach the bottom of the staircase, the vertical chute opens into a tall antechamber (thank you, God) with a concrete floor. The pinch between my shoulders lessens a little. The best way out is always through—one of Angela’s favorite quotes, and I don’t have a choice now.

Above a diagram of sediment layers displayed on the wall, large black arrows direct visitors into the next room. With each step forward, the arrangements of skulls lining the path become more frequent as the concrete gives way to dirt and the occasional puddle, but they’re oddly reassuring—they remind me of photos I found in Angela’s dissertation folders. If she can spend afternoons and evenings here, I should be able to.

Sibling rivalry propels me slightly faster down another tunnel with a stunted ceiling, like a string of dwarves once pickaxed their way through. Seb chatters on behind me, his voice a warm thrum.

“You were close to the truth earlier when you asked whether the Nazis named the catacombs. In fact, both the Nazis and the French Resistance used these tunnels to get around Paris during the Occupation. Angela found the matrix compelling for these reasons, and more.”

Hearing mention of the Nazis recalls the store clerk’s tattoo and the discomfort I felt last night. Another shot of unease stabs my belly. “Of course she did,” I reply.

The dull, flat scent of mold lies beneath the pervasive damp, like centuries of rot have taken hold deep within the catacombs, unaffected by the fresh air brought in by foot traffic from above. I retch when I get too close to a slimy wall. A shelf has been carved out of the rock and filled with sticks. When the light shifts, I realize they are femurs.

“Did you come here with Angela often?” I ask, averting my face, not wanting to see one more bone.