At no stage in the journey did he say where they were going. As in England, there was an almost complete absence of road signs, but eventually Prince recognised where they were, passing through Brondby and entering Copenhagen through its southern suburbs, heading towards the centre. It was getting dark when they reached Vesterbro, which he remembered well: it was where the Carlsberg brewery was based, and where his grandparents had lived until they started to climb the social ladder.

Despite her obvious snobbery, his grandmother could never quite leave Vesterbro entirely behind her. Although it was a working-class area, with factories and tiny cottages, it was the place she knew best and, he sensed, the area where she felt most comfortable, where she didn’t need to put on airs and graces. Most Saturdays they would take him to the Enghaveparken: if he was well behaved and sat still as they listened to whatever was being performed on the bandstand, not only would he then be allowed to visit the play area, but he would also be bought an ice cream.

Egon drove past Enghaveparken and on to Carstensgade. They were now in the north of Vesterbro and he was clearly having difficulty finding his way around. Prince was worried they were driving too slowly: nothing looked more suspicious than a vehicle crawling along, pausing too long at junctions. As they passed the street where Prince’s great-aunt had lived, and then the school his grandmother had gone to and which she always made a point of showing him, he was tempted to ask Egon what he was looking for, but thought better of it. He was, he remembered, the blind man being shepherded by others.

Egon let out a sudden and triumphant ‘Ah!’ and turned the van sharply into a narrow entrance, driving into the centre of a neat courtyard surrounded by identical white-painted apartment blocks, each eight storeys high, with heavy wooden doors. From under his seat he removed a small package and handed it to Prince.

‘These are your keys. The big one opens the main door to that block there – block D. You’re to go to the top floor, to apartment 30, understand? If there is a newspaper tucked under the door of the apartment, under no circumstances enter it. Leave the building immediately. But if there’s nothing under the door, use the smaller key here to enter. Lock the door when you’re inside but don’t bolt it. That is important. Understand?’

Prince said he understood, but Egon, whose nervousness was now all too obvious, made him repeat his instructions.

‘You go in now. I have to leave.’