“No,” he said, burying his face in his hands to hide the tears. “Of course not. Of course it wasn’t your fault.”

Later, on his way out of the country after being ordered to leave Leipzig and East Germany, he sought out Lothar for the final time and found him in the FDJ office at the university. He still had no clue as to Ilona’s whereabouts. The fear and anxieties that had driven him on for the first days and weeks had given way to an almost intolerable burden of hopelessness and sorrow.

In the office, Lothar was cracking jokes with two girls who were laughing at something he had said. They fell silent when he entered the room. He asked Lothar for a word.

“What is it now?” Lothar said without moving. The two girls looked at him seriously. All the joy was purged from their faces. Word of Ilona’s arrest had spread around the campus. She had been denounced as a traitor and it was said she had been sent back to Hungary. He knew that was a lie.

“I just want a word with you,” he said. “Is that okay?”

“You know I can’t do anything for you,” Lothar said. “I’ve told you that. Leave me alone.”

Lothar shifted round to entertain the girls further.

“Did you play any part in Ilona’s arrest?” he asked, switching to Icelandic.

Lothar turned his back on him and did not answer. The girls watched the proceedings.

“Was it you who had her arrested?” he said, raising his voice. “Was it you who told them she was dangerous? That she had to be removed from circulation? That she was distributing anti-socialist propaganda? That she ran a dissidents” cell? Was it you, Lothar? Was that your role?”

Pretending not to hear, Lothar said something to the two girls, who returned silly smiles. He walked up to Lothar and grabbed him.

“Who are you?” he said calmly. “Tell me that.”

Lothar turned and pushed him away, then walked up to him, seized his jacket by the lapels and thrust him against the filing cabinets. They rattled.

“Leave me alone!” Lothar hissed between clenched teeth.

“What did you do with Ilona?” he asked in the same collected tone of voice, not attempting to fight back. “Where is she? Tell me that.”

“I didn’t do a thing,” Lothar hissed. “Take a closer look, you stupid Icelander!”

Then Lothar threw him to the floor and stormed out of the office.

On the way back to Iceland he got the news that the Soviet army was crushing an uprising in Hungary.

He heard the old grandfather clock strike midnight, and he put the letters back in their place.

He had watched on television when the Berlin Wall fell and Germany was reunited. Seen the crowds scale the wall and hit it with hammers and pickaxes as if striking blows against the very inhumanity that built it.

When German reunification had been achieved and he felt ready, he travelled to the former East Germany for the first time since he had studied there. It now took him half a day to reach his destination. He flew to Frankfurt and caught a connection to Leipzig. From the airport he took a taxi to his hotel, where he dined alone. It was not far from the city centre and campus. There were only two old couples and a few middle-aged men in the dining room. Salesmen perhaps, he thought. One nodded at him when their gazes met.

In the evening he took a long walk and remembered the first time he had strolled around the city when he arrived there as a student, and he reflected on how the world had changed. He looked around the university quarter. His dormitory, the old villa, had been restored and now served as the headquarters of a multinational company. The old university building where he had studied was gloomier in the dark of night than he remembered it. He walked towards the city centre and looked inside Nikolaikirche, where he lit a candle in memory of the dead. Crossing the old Karl-Marx-Platz to Thomaskirche, he gazed at the statue of Bach that they had so often stood beneath.

An old woman approached him and invited him to buy some flowers. With a smile, he bought a small posy.

Shortly afterwards he went where his thoughts had so often returned. He was pleased to see that the house was still standing. It had been partly refurbished and there was a light in the window. Much as he longed to, he did not dare peek inside, but he had the impression that a family lived there. A television set gave off a flickering light from what had been the living room of the old landlady who had lost her family in the war. Everything inside would be different now, of course. Perhaps the eldest child was sleeping in their old room.

He kissed the posy of flowers, placed it at the door and made the sign of the cross over it.

A few years earlier he had flown to Budapest and met Ilona’s elderly mother and two brothers. Her father was dead by then, never having discovered his daughter’s fate.

He spent all day sitting with Ilona’s mother, who showed him photographs of Ilona from when she was a baby through to her student years. The brothers, who like him were beginning to age, told him what he already knew: nothing had come of their search for answers about Ilona. He could sense their bitterness, the resignation that had taken root in them long ago.

The day after he arrived in Leipzig he went to the old security police headquarters, which were still in the same building on Dittrichring 24. Instead of police at the reception desk in the foyer, there was now a young woman who smiled as she handed him a brochure. Still able to speak passable German, he introduced himself as a visitor to the city and asked to look around. Other people had entered the building for the same purpose, and walked in and out through open and unlocked doors, free to go where they pleased. When she heard his accent the young woman asked where he was from. Then she told him that an archive was being set up in the old Stasi offices. He was welcome to listen to a talk that was about to begin, then tour the building. She showed him to the corridor leading to where chairs had been arranged, every one of them occupied. Some of the audience were standing up against the walls. The talk was about the imprisonment of dissident writers in the 1970s.

After the talk he went to the office in the alcove where Lothar and the man with the thick moustache had interrogated him. The cell next door was open and he went inside. He thought again that Ilona might have been there. There were graffiti and scratches all over the walls, made with spoons, he imagined.

He had put in a formal application to look at the files when the Stasi archive opened after the fall of the Berlin Wall. Its purpose was to help people delve into the fate of loved ones who had gone missing, or find information about themselves that had been collected by neighbours, colleagues, friends and family, under the system of interactive surveillance. Journalists, academics and people who suspected they had been documented in the files could apply for access, which he had done by letter and telephone from Iceland. Applicants had to explain in detail why they needed to study the files and what they were looking for. He knew there were thousands of large brown paper bags full of files that had been shredded in the last days of the East German regime; a huge team was employed on taping them back together. The scale of the records was incredible.

His trip to East Germany produced nothing. No matter how he searched, he could not find a scrap of information about Ilona. Her file had probably been destroyed, he was told. Possibly she had been sent to a labour camp or gulag in the old Soviet Union, so there was a slim chance that he could find some record of her in Moscow. It was also conceivable that she had died in police custody in Leipzig or in Berlin if she had been sent there.

Nor did he find any information in the Stasi files about whichever traitor had turned his beloved girlfriend over to the security police.