In the saddle was Harald Olufsen, a tall youth of eighteen, with clear skin and fair hair brushed back from a high forehead. He looked like a Viking in a school blazer. He had saved for a year to buy the Nimbus, which had cost him six hundred crowns-then, the day after he got it, the Germans had imposed the petrol restrictions.

Harald had been furious. What right did they have? But he had been brought up to act rather than complain.

It had taken him another year to modify the bike, working on school holidays, fitting it in with revision for his university entrance exams. Today, home from his boarding school for the Whitsun break, he had spent the morning memorizing physics equations and the afternoon attaching a sprocket from a rusted lawn mower to the back wheel. Now, with the motorcycle working perfectly, he was heading for a bar where he hoped to hear some jazz and perhaps even meet some girls.

He loved jazz. After physics, it was the most interesting thing that had ever happened to him. The American musicians were the best, of course, but even their Danish imitators were worth listening to. You could sometimes hear good jazz in Morlunde, perhaps because it was an international port, visited by sailors from all over the world.

But when Harald drove up outside the Club Hot, in the heart of the dockside district, its door was closed and its windows shuttered.

He was mystified. It was eight o’clock on a Saturday evening, and this was one of the most popular spots in town. It should be swinging.

As he sat staring at the silent building, a passer-by stopped and looked at his vehicle. “What’s that contraption?”

“A Nimbus with a steam engine. Do you know anything about this club?”

“I own it. What does the bike use for fuel?”

“Anything that burns. I use peat.” He pointed to the pile in the back of the sidecar.