The tunnel could not be infinite. It must end eventually. He just had to keep crawling. The sense that he was lost in endless darkness was just childish panic. He had to stay calm. He could do that. Karolin was at the end of this tunnel—not literally, but all the same the thought of her sexy wide-mouthed smile gave him strength to combat his fear.

Was there a glimmer ahead, or did he imagine it? For a long time it remained too faint to be sure of; but at last it strengthened, and a couple of seconds later he emerged into electric light.

There was another shaft above his head. He went up a ladder and found himself in another basement. Three people stood staring at him. Two had luggage: he guessed they were escapers. The third, presumably one of the student organizers, looked at him and said: “I don’t know you!”

“Danni brought me,” he said. “I’m Walli Franck.”

“Too many people know about this tunnel!” the man said. His voice was shrill with anxiety.

Well, of course, Walli thought; everyone who escapes through it obviously knows the secret. He understood why Danni had said that the danger increased every time it was used. He wondered whether it would still be open when he wanted to return. The thought of being trapped in East Germany again almost made him want to turn around and crawl all the way back.

The man turned to the two with bags. “Go,” he said. They went down the shaft. Returning his attention to Walli, he pointed to a flight of stone steps. “Go to the top and wait,” he said. “When the coast is clear, Cristina will open the hatch from the outside. You get out. Then you’re on your own.”

“Thanks.” Walli went up the steps until his head came up against an iron trapdoor in the ceiling. This had originally been used for deliveries of some kind, he guessed. He crouched on the steps and forced himself to be patient. Lucky for him there was someone keeping watch on the outside, otherwise he might be seen leaving.

After a couple of minutes, the hatch opened. In the evening light, Walli saw a young woman in a gray head scarf. He scrambled out, and two more people with bags hurried down the steps. The young woman called Cristina closed the hatch. She had a pistol stuffed into her belt, he saw with surprise.

Walli looked around. He was in a small walled yard at the back of a derelict apartment building. Cristina pointed to a wooden door in the wall. “Go that way,” she said.

“Thank you.”

“Get lost,” she said. “Fast.”

They were all too stressed to be polite.

Walli opened the door and passed through to the street. To his left, a few yards away, was the Wall. He turned right and started walking.

At first he looked around constantly, expecting to see a police car screech up. Then he tried to act normally and saunter along the pavement as he had used to. No matter how he tried, he could not lose the limp: his leg hurt too much.