‘Shit!’ Nina yelped as someone took a punch to the face and missed her by inches as he fell. ‘Dammit, Eddie!’

But she knew why he had done it. The gunman and his companions were almost on them – only to be caught in the swelling chaos. The blond man had just enough time to lock eyes with her before a drunk in a tracksuit hurled himself bodily at him. Both men fell, vanishing amongst flailing fists and feet.

She saw gaps opening as the non-belligerents in the surrounding crowd tried to get clear. ‘Cheng, quick!’ she shouted, following Eddie and Krämer. A whistle shrilled, followed by another; the police were already responding.

Cheng behind her, she caught up with her husband. ‘Keep going,’ Eddie ordered, angling towards the side of the street as the approaching cops ran down its centre. ‘Once we’re clear of the fight, they won’t even look at us.’

‘You’re sure?’ she asked.

‘Do we look like a bunch of lads out on the piss?’

‘Good point.’

They moved towards the Reeperbahn, policemen charging past with batons drawn, and reached the little plaza of the Beatles-Platz. A police car pulled up to disgorge more officers. Eddie veered well clear as the cops ran for the side street, leading the foursome past the other Fab Four. ‘Over the road, quick!’

He led them across the Reeperbahn, ducking into the crowds outside the bars and heading for the first side street. ‘Down here,’ he said, looking back. If their pursuers had escaped the brawl, they hadn’t yet made it to the Beatles-Platz. ‘You know your way around here?’ he asked Krämer.

The German nodded. ‘There is a park along this road,’ he said. ‘We can go through it to the red-light district. There are always lots of people. We can lose them.’

They jogged down the side street, Krämer still hobbling. ‘So you don’t know who “they” are?’ Nina asked.

‘No,’ he replied. ‘I lied to you about the other buyers. I was trying to get more money.’

‘But you must have spoken to someone. Otherwise how would they have known where you were?’

‘I spoke to no one!’ Krämer insisted as they entered the park. ‘I only gave my address to Mr Hui.’ He glanced at Cheng. ‘I never saw those men before – and I do not know how they found me.’

‘They might be spooks,’ Eddie suggested. Krämer didn’t understand the slang. ‘Intelligence services,’ he clarified. ‘Spies.’

‘Spies?’ The sailor looked unnerved. ‘Working for who?’

‘How would I know? The blond guy sounded Scandinavian, but I don’t know why anyone from IKEA-land would want to take the key from you.’

‘Speaking of the key,’ said Nina, ‘have you still got it?’

Krämer had kept the artefact inside his jacket. ‘Yes. I have decided . . . it is too much trouble. You can have it. For the fifty thousand euros.’