Minutes ticked past, and no light appeared at the windows he knew to be hers. What was going on? He knew from watching her previously that as soon as she walked in, a glow from the hall could be seen at the living-room window. Yet the rooms remained in darkness. Had he made a mistake? Was he watching the wrong window? He counted them off from the first-floor corner window, just to be sure.

That was when he saw her. Unmistakably. But she was in the wrong place. Instead of being on the third floor, she was on the first. And she was with a man who definitely wasn’t Tadeusz Radecki. As he watched, they moved closer together, clearly having some sort of intense conversation. Then they were in each other’s arms.

The bitch had come straight from Radecki’s apartment to this other man’s embrace. Rado reached for his phone. This was something his uncle needed to know about. And fast.

Krasic was there inside twenty minutes. He’d run every amber light the length of the Ku’damm in his eagerness to discover Caroline Jackson doing something she shouldn’t be doing. He parked across somebody’s garage entrance and barrelled up the street to his nephew’s vantage point. ‘What’s happening?’ he demanded.

Rado pointed up to the oblong of light on the first floor. ‘That’s where she was. Her and this bloke. Tadeusz’s driver dropped her off and her lights didn’t go on. Next thing was, I spotted her in the first-floor window with him. They were talking, then they were snogging. Then they disappeared. So I’d say at a rough guess that they’re shagging, wouldn’t you?’

‘I told him not to trust her,’ Krasic growled. ‘So what number is this apartment?’

‘It’s two floors below hers. If she’s 302, he must be in 102.’ As he spoke, the man came into view again. ‘That’s him, Uncle. That’s the man she was with,’ he exclaimed excitedly, pointing up to the window as Tony crossed from one side to the other before disappearing again.

Krasic chopped Rado’s arm to his side with a savage blow. ‘For fuck’s sake, Rado, do you want the whole street to see us?’

Rado clutched his aching arm and squirmed with the pain. ‘Sorry, Uncle.’

‘Never mind. You did a good job, spotting the bitch. Now I need to find out who her fancy man is. It’ll have to wait till morning.’ He was speaking to himself more than to his nephew. Krasic stared up at the window like a moonstruck hare, an intent frown on his face.

Time passed. Rado fidgeted, but Krasic stood immobile as stone. His military training had taught him the importance of being able to watch without being seen. Then, his life had depended on it. He wondered if that might be the case again.