Crimm was an experienced seaman. His father had brought him up on the ocean; his mother, fond but resentful, said her son had spent more of his boyhood on boats than at home. And at sea, you learned to keep calm. You tried one way. If that failed, you tried another. And if that failed in turn, another yet.

‘We get out on the ice. Fix up ropes. We go on foot, and haul the ship back until we find an open lead.’

‘Hmm,’ Ayto said. ‘Look how quick it’s closing up. We wouldn’t get far.’

‘So your idea is . . .’

‘We wait. Overnight if we have to. Maybe the weather will relent a bit tomorrow. If the leads open up again we might make a break.’

Crimm thought about that, looking out to the horizon. Everywhere the ice was solidifying, those great ridges thrusting into the air where the floes collided. Even the drifting bergs were getting frozen into the congealing pack. ‘This stuff doesn’t look as if it’s going to give up any time soon.’

‘Well, it should,’ Ayto said, almost resentful. ‘It’s not even the equinox yet, unless I got too drunk to remember. I say we camp for the night and hope the little mother of the sky looks a bit more kindly on us in the morning.’

So Crimm gave in. They shipped the oars and set up the mainsail as a makeshift shelter suspended from the main mast. They had a small stock of firewood they carried to warm themselves in the nights at sea, and Aranx started building a fire out on the ice. Another man broke out dried fish and biscuits for a meal. Another, a Muslim, rolled out his prayer mat on the ice and knelt, facing east.

Two more of the crew went on a hopeful quest across the ice in search of driftwood for fuel. Ayto called after them, ‘Walk where the ice looks blue. That’s where it’s oldest, thickest. If you fall in through a crack I won’t be coming after you.’

Crimm walked around the ship, looking for damage to the timbers from the ice scrapes. He could hear the ice around him groaning and creaking as it consolidated. It was an eerie sound, laid over the silence of the enclosed, hushed sea, and the surface shuddered and lurched constantly.

And then, he actually saw it begin, the boat’s planking cracked and crumpled inward, under the relentless pressure from the ice, giving way with a snapping, splintering noise. The hull started to tilt.

‘Everybody off,’ he called. ‘Off the ship, now! Grab what you can . . .’

They all got off in time, as the hull crumpled like an empty eggshell. The deck tipped over, and the remaining mast gave way with a snap. It all happened quickly, in heartbeats.