“Whoa, wait.” The old man grabbed urgently at Alex’s arm. “Alex. Listen to me. None of that. It wasn’t your fault. My fault, for dragging you into it. You only did what you had to. You saved me, son. The girl jumped. He jumped after her. They got themselves in that situation, and they’ve been in far worse places before. Believe me, they wouldn’t have thought twice about—”

“But he was—”

“Alex, listen,” his grandfather broke in. “I’m truly sorry I’ve not been in touch. I should have been here to help you. Talk to you. But, well, y’see, things got a little busy. Ever since Prague, Harry and I have been—”

There it was. “Harry,” Alex said. “I need to ask you about Harry—”

“Well. That makes two of us. It’s Harry I’m here to talk to you about, Alex. Harry’s . . . Harry’s in a very bad predicament.”

“What?”

“Seriously, Alex. Bad trouble. Literally life and death.”

The clamor of questions in Alex’s head was silenced as thoughts of Harry came slicing through. He had spent only a few intense days with the man, yet he thought of Harry as one of the best friends he’d ever had. Harry had told him they had actually met once years before, at a time Alex couldn’t remember, back when he was still that very small and sickly child, the object of curiosity for countless baffled doctors. Knee-’igh to a baby grass’opper, Harry had put it.

He thought again of the photograph Harry had shown him: Harry a child himself, maybe six or seven, standing by Alex’s grandfather in their vanished black-and-white world. His grandfather wore a military uniform and looked somewhere in his fifties. Harry had been orphaned during the Second World War, hiding among bombed buildings in London. He’d said Alex’s grandfather had taken him under his wing.

It didn’t make sense. The old man and Harry looked roughly the same age now. But it suddenly hit Alex: if what Harry said were true, then Harry was more than an old friend to his grandfather. He was practically an adopted son.

“What’s wrong? What’s happened to Harry?” Alex said.

His grandfather spoke very quietly: “They got him, Alex . . . Your tall man. Zia.”

“What?”

“They didn’t die that night. I don’t suppose I ever believed for a second they were really gone.”

“Alive?”

“Bad as ever,” his grandfather went on. “Worse. And they’ve got Harry. We need to get Harry back, Alex. You and I. I need you to help me get Harry back. You and that.” He pointed at the old toy standing between them on the table. “You’ve used it before. You can use it again.”