As Elena and he followed Bonhoeffer, Martin realised that there were two anchors, one each for the port and starboard sides. The two large chain winches were separated in the middle by a podium, on which sat a box with a number of levers. Each large winch had a metal brake wheel which you had to rotate like a valve if you wanted to let the anchor down or stop it falling.

‘What exactly are we looking for here?’ the captain asked on the podium, with his back to the brake wheel for the port anchor. ‘Surely not Anouk’s hiding place?’

Martin allowed his gaze to wander around the anchor room.

He was surprised by how clean everything was, almost sterile. Given the prevailing smell in here, he would have expected rust and oil dotted on the floor, or at least signs of weathering from the aggressive salt water, which kept splashing up through the holes. But even in the non-public areas, cleanliness and tidiness were the order of the day. Everything looked as if it had been newly renovated. The walls were painted white, the floor laid with thick rubber mats to stop you from slipping even when it was wet.

Huge amounts of space.

But not a place you could survive for weeks. It was draughty, cold and damp. You’d get pneumonia within a week. In any case at least two sailors would enter this room to weigh anchor each time the ship came into port.

She can’t have been here.

Elena seemed to share Martin’s unspoken assessment. ‘This is a dead end,’ she shouted. She sounded shrill and several years younger when she had to raise her voice.

Martin nodded. They’d clearly got carried away. Just idle speculation, he thought, his irritation brewing. Treating a child’s drawing as important evidence was just as foolish as seeing the face of the Virgin Mary in a slice of toast.

‘Let’s go.’ As Martin bent down to tie the laces of his boots, which had come undone, he found himself looking below the first step of the platform.

‘Where’s the chain?’ he asked Bonhoeffer. The captain looked down at him blankly.

Martin pointed to the large metal reel to his left. ‘I can only see the few metres that run from the huge wheel to the anchor shaft. Where’s the rest?’

‘Right where you’re kneeling,’ Bonhoeffer replied, getting down from the platform. He stamped his foot. ‘Right under here.’

‘Is there space down there?’

Bonhoeffer wiggled his outstretched hand, as if trying to imitate a rocking boat. ‘Depends how much of the chain is hauled in. But there’s always a bit of room. It’s actually a favourite hiding place for stowaways. But they could only last a few days down there, not weeks.’

‘Is there access to it?’ Martin asked nonetheless. He rapped his knuckles on the metal plate he was squatting on.