“Many things,” he said, his voice husky.

“Such as?”

He glanced at me and smiled.

“You. The children. Work. The moon.”

“Always the moon,” I said softly.

“When I was a little boy and I went to live with Adele, I promised myself I’d never forget my family,” he said quietly. “I remember sitting in that car with her, utterly terrified, deciding that I’d hold their memories so close that I’d never lose them. Then time began to pass, and one by one, the memories slipped away. Now I only remember a handful of things… How ordinary it was as we ate breakfast together. The air raid siren and the panic as my mother went to get the baby and my father shoved me into the cellar—then nothing, until I woke up in the hospital. I do remember the night before. I stayed up late with my father, staring at the moon with this terrible telescope he’d constructed himself. He was an amateur astronomer, obsessed with the moon. He told me that night that he hoped man would reach it in my lifetime.”

“You’ve never told me any of that,” I said, stunned. “You always said you didn’t remember anything.”

“You’ve always been so much more outgoing than me, Sofie. I’ve had to share parts of myself with you over the years that were hard to expose—but those memories of my family were just too precious, and part of what made them so was that they were only mine.”

“Why tell me now?”

“I’ve been thinking about those memories a lot lately. It brings me comfort that I don’t remember much about my parents. After all, no real sense of who they were means no way to know how they’d have felt about the work I’m doing now.”

He said this casually but I heard the pain behind his words, and it left me stricken.

“Jürgen…”

“Name a European city you love and German rockets may one day wipe it off the face of the earth.”

I gasped. “Are you close to that?”

“The components are all there. In theory—the rest is just a matter of persistence and experimentation to make those components work consistently.” He didn’t sound optimistic or proud. His tone was heavier than ever.