Prince leaned forward, ready to concentrate on what she was about to say.

‘Not now,’ she continued, ‘it’s far too late. Or too early: I never really know whether four o’clock in the morning counts as early or late.’ She looked at Prince as if she half expected him to decide for her.

‘But there’s a curfew, isn’t there? How could you get here during the curfew?’ Prince hesitated, worried he might be sounding anxious.

‘We’ll talk about all these things in the morning, or at least later in the morning. I need to get some sleep before then. I’ve been up since six o’clock; that’s getting on twenty-four hours.’

‘How come?’

‘Work.’

‘What do you do?’

‘Later: we’ll talk about all that later. There are two things I want to say before I get some sleep. Firstly, this is the last time we speak in English. It’s too risky and I’m told your Danish is excellent. You need to be speaking it all the time, though. You must get out of the habit of speaking English. Understand? Forsta?’

Prince nodded and said he understood. What was the second thing she wanted to mention?

‘How about you sleep on that couch and I take the bed?’

When Richard Prince had joined the police as an enthusiastic eighteen-year-old, he’d spent the first few months after his initial training on the beat. He didn’t last long walking the streets of Lincoln: early on, his superiors spotted him as a very bright grammar school boy who could easily have gone to university and clearly was destined for greater things. Before he’d completed his first year in the police, he was already a detective.

Life on the beat, as brief as it was, had a pre-ordained quality to it. Pinned on the inside of his bedroom door in his lodging house was his rota: he knew weeks in advance whether on any given day he’d be on a shift starting at six in the morning, two in the afternoon or ten at night. And when he arrived to start his shift at the police station in Church Lane, in the lee of the cathedral, the large board by the duty sergeant’s desk informed him which beat he’d been allocated to: West Common; South Commons; Castle & Cathedral; Station and St Mark’s; Canwick; Washingborough, or one of half a dozen others. And then there were the carefully drawn maps of each beat he’d tuck inside his notebook, showing a suggested route, which streets to pay special attention to, and the pubs to keep an eye on.