He manoeuvred a boat hook to snag the man’s coat. Straining, he pulled him across the ice until he was almost within reach. The floe rocked, bumping the lifeboat. Krämer cursed, then stretched out as far as he dared. His gloved fingers caught fabric; he clutched it tightly and hauled the unconscious man to the boat’s side.

The ice tipped again, sending a freezing splash over the man’s legs. He flinched, but his rescuer now had a firm hold. Figueroa joined in, and they brought the limp figure aboard.

Krämer examined him. The man was young, his face pale from the cold. If he had spent much longer exposed to the elements, he would be dead. ‘Get us back to the ship, fast,’ the German said. Figueroa returned to the outboard and brought the boat around. ‘We got you,’ Krämer said, trying to reassure the survivor. ‘You are safe.’

The man’s eyes snapped open. The sailor felt a sudden unease; he was looking through rather than at him, the gaze almost manic in its terrified intensity. ‘Demon . . .’

Krämer blinked at the feeble whisper. ‘What?’

‘Demon . . .’ the man in red repeated. His accent sounded Dutch. ‘In the ice. Sanna woke it . . . it killed her! We took the key. We took the key!’

Krämer realised his passenger was clutching something tightly to his chest. He looked more closely – and saw a glint of metal.

Gold.

‘We woke the demon,’ the young man went on. His breathing quickened. ‘It killed Sanna – killed everyone!’

Krämer was more interested in what he held than his words. Demons? His near-death had obviously driven him mad. He shifted to block Figueroa’s line of sight with his body, then started to prise the man’s fingers open.

‘No, no!’ gasped the Dutchman. ‘The key – don’t give it the key!’

‘We will be at the ship soon,’ said Krämer loudly, trying to drown out his voice. He finally forced the young man’s hands apart and tugged the object free. ‘It’s okay.’

‘No!’ he cried again. ‘They killed, they . . .’ He slumped in exhaustion.

‘It’s okay,’ Krämer said again, giving Figueroa a surreptitious glance before examining his prize.

What it was, he had no idea. It certainly didn’t look like a key. A plate-sized metal disc, its central hub inlaid with a circle of polished purple stone, into which was set a large crystal. At first he had thought the object was gold, but now he saw it wasn’t quite the right colour, with a distinctly reddish tinge. Writing was inscribed in its surface, but he didn’t recognise the language.

He turned it over. Both the stone and the crystal continued all the way through its centre. More unknown words ran around them.

One symbol was unmistakable, though.

A skull.