There were appreciative murmurs from the settlers. “It’s like a mountain,” said the woman sitting behind March. She was with her husband and four boys. They had probably been planning this trip all winter. A Tourist

Ministry brochure and a dream of April in Berlin: comforts to warm them in the snowbound, moonless nights of Minsk or Kiev, a thousand kilometres from home. How had they got here? A package tour organised by Strength-Through-Joy, perhaps: two hours in a Junkers jet with a stop-off in Warsaw. Or a three-day drive in the family Volkswagen on the Berlin-Moscow Autobahn.

Pili wriggled out of his father’s grasp and walked unsteadily to the front of the coach. March pinched the bridge of his nose between thumb and forefinger, a nervous habit he had picked up — when? — in the U-boat service, he supposed, when the screws of the British warships sounded so close the hull shook and you never knew if their next depth charge would be your last. He had been invalided out of the navy in 1948 with suspected TB and spent a year convalescing. Then, for want of anything better to do, he had joined the Marine-Kustenpolizei, the Coastal Police, in Wilhelmshaven as a lieutenant. That year he had married Klara Eckart, a nurse he had met at the TB clinic. In 1952, he had joined the Hamburg Kripo. In 1954, with Klara pregnant and the marriage already failing, he had been promoted to Berlin. Paul — Pili — had been born exactly ten years and one month ago.

What had gone wrong? He did not blame Klara. She had not changed. She had always been a strong woman who wanted certain simple things from life: home, family, friends, acceptance. But March: he had changed. After ten years in the navy and twelve months in virtual isolation, he had stepped ashore into a world he barely recognised. As he went to work, watched television, ate with friends, even -God help him — slept beside his wife, he sometimes imagined himself aboard a U-boat still: cruising beneath the surface of everyday life; solitary, watchful.