Unless the cops could be distracted.

They were not much older than Walli. He was sixteen, they seemed about twenty. They were looking around in confusion, their newly lit cigarettes between their lips, unable to figure out why a slate had shattered and two stones had been thrown.

“Pig-faces!” Walli yelled. “Shitheads! Your mothers are whores!”

They saw him then. He was a hundred yards away, visible despite the mist. As soon as they set eyes on him they started to move toward him.

He backed away.

They started to run.

Walli turned and fled.

At the cemetery gate he looked back. One of the men had stopped, no doubt realizing they should not both leave their post at the Wall to chase someone who had merely thrown stones. They had not yet got around to wondering why anyone would do something so rash.

The second cop knelt down and aimed his gun.

Walli slipped into the cemetery.

• • •

Bernd looped the clothesline around a brick chimney, pulled it tight, and tied a secure knot.

Rebecca lay flat on the roof ridge, looking down, panting. She could see one cop pounding along the street after Walli, and Walli running across the cemetery. The second cop was returning to his post, but—luckily—he kept looking back, watching his colleague. Rebecca did not know whether to be relieved or horrified that her brother was risking his life to divert the attention of the police for the next few crucial seconds.

She looked the other way, into the free world. In Bernauer Strasse, on the far side of the street, a man and a woman stood watching her and talking excitedly.

Holding the rope, Bernd sat down, then slid on his bottom down the west slope of the roof to the edge. Next he wound the rope twice around his chest under his arms, leaving a long tail of fifty or so feet. He could now lean out over the edge, supported by the rope tied to the chimney.

He returned to Rebecca and straddled the ridge. “Sit upright,” he said. He tied the free end of the clothesline around her and tied a knot. He held the rope firmly in his leather-gloved hands.

Rebecca took a last look into East Berlin. She saw Walli nimbly scaling the fence at the far end of the cemetery. His figure crossed a road and vanished into a side street. The cop gave up and turned back.

Then the man happened to look up, toward the roof of the apartment building, and his jaw dropped in astonishment.

Rebecca was in no doubt about what he had seen. She and Bernd were perched on top of the roof, clear against the skyline.

The cop shouted and pointed, then broke into a run.

Rebecca rolled off the ridge and slowly slid down the slope of the roof until her sneakers touched the gutter at the front.

She heard a burst of machine-gun fire.

Bernd stood upright beside her, bracing himself with the rope tied to the chimney.