‘Stop lying,’ Tadeusz said, his voice gentle and sad. ‘I know the truth. What is it they call it? A black operation. The sort of devious shit that never becomes public. I know what you people did. You killed the woman I loved because she looked like Carol Jordan. And then Carol Jordan moved in on me. Advised, no doubt, by your psychological expertise.’

Fuck, Tony thought. If that’s what they believe, there’s no way out of this. But he had to keep trying. ‘No, please. That’s not how it was. Look, Carol isn’t a cop any more, but she still has friends who are. One of them showed her a photograph of Katerina, after she died, not before. Because he thought it was amazing how alike they were.’ He paused to draw breath. The fact that nobody had hit him again gave him hope. ‘She decided off her own bat to take advantage of that. She decided she was going to get into bed with you. Literally and metaphorically.’ Big words for a battered man, he couldn’t help thinking irrelevantly. ‘I had to come to Germany for this murder investigation. The killer who’s targeting psychologists. You must have seen it on the news?’

Tadeusz and Krasic exchanged a quick look. Tony thought he saw a trace of uncertainty in their eyes. ‘I’m telling the truth,’ he said, almost sobbing. ‘I thought I could talk Carol out of what she was doing, get her back on track somehow. I love her. I don’t want her to be on the opposite side of the fence.’ He forced himself to cry, racking sobs that made his ribs scream in pain.

‘So what were you doing here, checking out the barges?’ Krasic demanded, his fist crashing into Tony’s ribs, smashing his opposite shoulder into the cold steel bulkhead.

Tony screamed with the pain, folding his arms across his chest. This time, the tears were real. ‘We’ve got a suspect,’ he gasped. ‘For the murders. We think he’s a bargee. His boat’s here. The Wilhelmina Rosen. Please, you’ve got to believe me,’ Tony begged. He wiped the strings of snot from his nose, trying not to think about the blood streaking them.

‘It’s a good story,’ Tadeusz said. Krasic looked at him as if he’d gone mad. ‘It’s a really good story. It’s almost good enough to be true.’

‘Boss,’ Krasic protested.

Tadeusz raised one finger. ‘It’s OK, Darko. There’s a very simple way to prove whether it’s true or not. We’re going to take our good friend Dr Hill back to Berlin with us. We’ve got a warehouse we can store him in temporarily. And then we run our little test.’

‘What test?’ Krasic said suspiciously.

‘If he’s telling the truth, then Carol Jordan won’t have any compunction about fucking me, will she?’