Because the generators had been switched off, the stabilisers weren’t working either. Each wave that slapped against the ship’s side sounded twice as loud, and the rolling and pitching of the liner were more pronounced than ever.

‘Maintenance,’ Bonhoeffer said, his hand already on the handle of the door that concealed the narrow private staircase to the bridge.

Martin didn’t believe a word. ‘Maintenance? In the middle of the night?’

Before leaving his cabin he’d thrown on a few clothes he’d bought yesterday in the on-board shop. As he hadn’t intended to stay on the Sultan, he’d boarded only with a change of socks and pants. Now he was wearing a grey, old-style polo shirt with the cruise line’s emblem and a pair of black jeans that he had to turn up as they were much too long. But he hadn’t bought himself another pair of shoes, which is why he was now standing beside the captain barefoot. It was only thanks to his quick reactions that he’d avoided being soaked through again. On the way to see Bonhoeffer he’d almost crashed into a drunk passenger staggering out of the ship’s disco on deck 11, carrying a neon drink that glowed in the dark.

‘I’ve really got my hands full at the moment,’ Bonhoeffer said in an attempt to get rid of him. ‘I have to…’ The captain let his hand slide off the doorknob and made a weary gesture mid-sentence as if all efforts would be in vain. ‘What the hell, I’ve got to make an announcement anyhow; you might as well hear it from me first.’

‘Another Passenger 23?’ Martin speculated.

Bonhoeffer nodded. The deep bags beneath his eyes looked as if they’d been made up. He pinched the bridge of his nose, which now was only covered with a thick plaster. ‘Lisa Stiller, fifteen years old, from Berlin. We’re showing her picture on the on-board television, just in case someone’s seen her. She’s a victim of cyberbullying and she left a farewell note.’

‘When?’ Martin turned his arm to look at the watch on his wrist, and even that movement pulled painfully on his shoulder muscles. On the other hand, his toothache and headache had both gone for the time being.

‘When did she probably go overboard? Mother and daughter had dinner till 21.44, then the two of them retired to their cabins. According to the computer log Lisa last used her key card at 21.59.’

Leaving a window of three hours at most.

In that time the Sultan would have done a good fifty nautical miles.

‘What do the security cameras say?’

‘Nothing.’