They drove to Checkpoint Charlie.

They went through a barrier and into a long shed where they had to hand over their passports. Then they were asked to wait.

The border guard who had taken their passports went away. After a while a tall, stooped man in a civilian suit ordered them to get out of their Mercedes and follow him.

The man strode ahead, then looked around, irritated at Fitz’s slowness. “Please hurry,” he said in English.

Dave remembered the German he had learned in school and improved in Hamburg. “My grandfather is old,” he said indignantly.

Fitz spoke in a low voice. “Don’t argue,” he said to Dave. “This arrogant bastard is with the Stasi.” Dave raised an eyebrow: he had not previously heard Fitz use bad language. “They’re like the KGB, only not so softhearted,” Fitz added.

They were taken to a bare office with a metal table and hard wooden chairs. They were not asked to sit, but Dave held a chair for Fitz, who sank into it gratefully.

The tall man spoke German to an interpreter, who smoked cigarettes as he translated the questions. “Why do you wish to enter East Germany?”

“To attend the funeral of a close relative at eleven this morning,” Fitz answered. He looked at his wristwatch, a gold Omega. “It’s ten now. I hope this won’t take long.”

“It will take as long as necessary. What is your sister’s name?”

“Why do you ask that?”

“You say you wish to attend the funeral of your sister. What is her name?”

“I said I wanted to attend the funeral of a close relative. I did not say it was my sister. You obviously know all about it already.”

This secret policeman had been waiting for them, Dave realized. It was hard to imagine why.

“Answer the question. What is your sister’s name?”

“She was Frau Maud von Ulrich, as your spies have obviously informed you.”

Dave noticed that Fitz was getting annoyed, and breaking his own injunction to say as little as possible.

The man said: “How is it that Lord Fitzherbert has a German sister?”

“She married a friend of mine called Walter von Ulrich, who was a German diplomat in London. He was killed by the Gestapo during the Second World War. What did you do in the war?”

Dave saw, from the look of fury on the tall man’s face, that he had understood; but he did not answer the question. Instead he turned to Dave. “Where is Walli Franck?”

Dave was astonished. “I don’t know.”

“Of course you know. He is in your music group.”

“The group has split. I haven’t seen Walli for months. I don’t know where he is.”

“This is not believable. You are partners.”

“Partners fall out.”

“What is the reason for your quarrel?”

“Personal and musical differences.” In truth the differences were purely personal. Dave and Walli had never had any musical differences.

“Yet now you wish to attend the funeral of his grandmother.”