I parked my car off to the side according to the guard’s instructions and walked through the gates. Aldo was waiting for me beside a small khaki truck. He looked unsure, glancing between me and the entrance to the tunnel.

“He’s quite a way in…”

“That’s okay,” I said, forcing a confident smile. “I’m not in any hurry.”

I took the front passenger’s seat and Aldo started the car. As the engine ignited, he glanced at me one last time.

“It’s not pleasant in there, Sofie,” he said, his voice low. “Are you sure you want to do this? I know Helene Schönerer is well familiar with the camps, but even she found it to be…too much.”

“I’m just here to see Jürgen,” I said firmly. “Let’s get this over and done with.”

He sighed and nodded, then steered the car beneath the crane’s frame.

“Wind up that window, please.” I did as I was instructed, and Aldo did the same on his side, as the car moved into the mouth of the tunnel.

Inside, the light was much dimmer, and at first, it was hard for me to see. As my eyes adjusted, I saw dozens of men working at tables and on components on flatbed train trolleys. Aldo drove slowly, driving around some of these stations, crossing each of the train tracks at different times to avoid carriages left in place. As we moved farther along, the air in the car became so pungent, my stomach rolled with every breath.

“What is that smell?” I asked Aldo. I covered my nose with my hand and tried to breathe through my mouth, but even inside the sealed car, I could taste the filth.

“We had to move quickly after the Peenemünde site was bombed, and we’ve had high quotas to meet for the V-2s. There was no time to install sanitation or ventilation…”

Now a few hundred feet into the tunnel, I saw a rough-hewn cross tunnel that seemed to have been cut by hand, the texture of the walls and ceilings coarse and uneven. I was startled to see rows of wooden bunks in the tunnel, most without even a mattress on them, and beside these, drums lined up, one after the other. A man sat on the last drum. His striped trousers were down around his ankles, but he seemed unconscious, leaning back against the wall behind him, his mouth wide and his eyes vacant as he stared at the ceiling. I gasped involuntarily and squeezed my eyes shut.

“They…the prisoners live in here?”

I looked out the window again, and now noticed the slumped shoulders of the men as they worked.