Walli left and used the other bathroom, but it took all his strength.

The postman brought his mail, including letters forwarded from London by Mark Batchelor, Plum Nellie’s manager. One was addressed in Karolin’s handwriting and had an East German stamp. Walli set it aside to read later.

It was a normal day in Haight-Ashbury. A musician friend strolled in and they started writing a song together, but it came to nothing. Dave Williams and Beep Dewar stopped by: Dave was living at her parents’ house and looking for a property to buy. A dealer called Jesus dropped off a pound of marijuana and Walli hid most of it in the cabinet of a guitar amplifier. He did not mind sharing; but, if he did not ration it, all of it would be gone by nightfall.

In the evening Walli went to a diner with a few friends, taking Tammy and Lisa. Four years after leaving the Soviet bloc he still marveled at the abundance of food in America: big steaks, juicy hamburgers, piles of French fries, mountainous crisp salads, thick milk shakes, all for next to nothing, and coffee with free refills! Not that such food was expensive in East Germany—it just did not exist there at all. Butchers were always short of the best cuts of meat, and restaurants grumpily served mean portions of unappealing food. Walli had never seen a milk shake there.

Over dinner Walli learned that Lisa’s father was a doctor serving the Mexican community in Dallas, and that she hoped to study medicine and follow in his footsteps. Tammy’s family ran a profitable gas station, but her brothers would take it over, and she was going to art school to study fashion design with the aim of opening a clothing store. They were ordinary girls, but this was 1967 and they were taking the pill and they wanted to get laid.

It was a warm night. After eating they all went to the park. They sat down with a group of people singing gospel songs. Walli joined in, and no one recognized him in the dark. Tammy was tired after the bus journey, and she lay down with her head in his lap. He stroked her long blond hair and she went to sleep.

A little after midnight, people began to leave. Walli strolled home, not noticing until he got there that Tammy and Lisa were still with him. “Do you to have a place to spend the night?” he said.

Tammy said in her Texas accent: “We could sleep in the park.”

Walli said: “You can crash on my floor if you want.”

Lisa said: “Would you like to sleep with one of us?”

Tammy said: “Or both?”

Walli smiled. “No, I have a girlfriend, Karolin, back in Berlin.”

“Is that true?” said Lisa. “I read it in the paper, but . . .”

“It’s true.”

“And you have a baby daughter?”

“She’s three years old, now. Her name is Alice.”

“But no one still believes in fidelity, and all that crap, do they? Especially not in San Francisco. All you need is love, right?”