I moan in response from where I lie flat on the ground. All over my body throbs with ache, though the pain is mostly confined to my arm. Seb splinted my elbow, but it’s now swollen to the size of a baseball.

“Mmm.”

“Shayna,” she tries again. “Seb left for more antiseptic from the hospital. We’re alone.” Angela speaks slowly, like the effort taxes her. The crushing verity of her words brings on new panic that constricts my chest and fat tears that sting. Angela was limping earlier, too; we’re alone and both injured.

I roll to my side and struggle to an upright position. Zip ties bind my feet and hands in front of my body, and I note the plastic’s sharp sensation, like it might slice through my skin at the right angle. “How long ago?” I ask, rubbing my wrists with opposite fingers.

“About five minutes,” Angela says.

I lift my head and stifle a cry. Bones form a crisscrossing pattern from floor to ceiling on the wall opposite Angela and surround two complete skeletons side by side. The skeletons stand the exact same height, mirror images of each other.

“Did you forget where we were?” she asks.

I shake my head, recalling Angela’s research. A room filled with fibulae, a room devoted to soldiers, and a room full of twin bones. The twin room. “Just disoriented.”

Books, chemicals in industrial-size jugs, cords and cables looped in precise rings, and an illuminated construction lamp are piled in a corner, throwing shadows around the room. Only one wall contains a bone mosaic, while the other wall, behind Angela, appears to be constructed from bones stacked on top of one another. Behind me, overhead, hangs a rectangular board of felt nailed into the compacted dirt wall, covered in graph paper, newspaper articles, handwritten notes, and maps with places circled in red pen. A large, knee-high generator occupies a corner, beside a refrigerator, displaying dozens of vials and thin tubes visible from its glass door. When we first entered, I tried to reverse, scratched back into the corridor, but Seb caught me. He said he would always catch me.

“We have to get out of here.” Angela struggles with her ties five feet away from me, her back against the wall of stacked bones. The bones clink together behind her jerking movements. “He’ll be back soon—the hospital is in the next arrondissement.”

My limbs are heavy. Exhausted from the adrenaline rush of terror bursting from every pore.

Six million unknowns is about to become six million and two.

“Shayna,” Angela hisses. “Snap out of it!”