‘The machine didn’t show any striking fluctuations,’ she said. ‘In any event, where you pieced together from hearsay all those things you weren’t personally witness to, polygraphic assessment isn’t much use. But at one point…’ She turned the laptop to face him. ‘Here you start to sweat and your heart rate shoots up. Even without the camera, I also detected various microexpressions that signalled to me you weren’t telling the truth.’ She showed him a section of graph where the waves looked like the ECG of someone on the verge of cardiac arrest.

‘What was I saying then?’ Martin asked, even though he had a very good idea.

‘You were basically telling Dr Beck that you hadn’t seen anything in Shahla Afridi’s notes referring to your son’s fate.’

Martin nodded.

‘That was a lie, wasn’t it?’

He swallowed deeply, but didn’t say anything.

‘Herr Schwartz, it won’t change my assessment one bit. As far as I can see, you’ve not done anything wrong except take absence without leave. I’m only interested privately in what you found out about Timmy and Nadja.’

Oh, really? Are you? Why? For a bit of sensationalism, perhaps?

Looking into her good-natured eyes he knew he was being unfair on her.

‘The video that Bonhoeffer showed you. Where you see them jumping from the ship,’ she insisted. ‘You know now why the larger shape went first, followed by the smaller one, don’t you?’

Martin gave a terse nod. He’d learned the truth three days following Shahla’s death, after the Sultan had berthed in New York and the FBI had taken up the investigation. By that point Daniel’s men had already located the secret place near the blue shelf where the chambermaid had hidden Anouk for the last few weeks, and which had also been Lisa’s hiding spot during the night she faked her suicide. In the bare, container-like room, which had been used to store recyclable metal and other raw materials before the waste dumping facility was decommissioned, they’d found a mattress, a banana crate that had served as a bedside table and a metal shelf unit screwed into the wall with books, children’s games, puzzles, cuddly toys and even an iPad full of films, e-books and computer games.

Besides the multimedia content, FBI technicians discovered in the browser a link to a cloud server where Shahla had stored personal documents. After they’d managed to crack the code, they came across a diary entry relating to the day when Timmy and Nadja died. In a break during questioning, the chief FBI investigator had left Martin alone with an extract from the diary.