Hickey is staring fixedly out beyond the icicle-sheathed bowsprit, the foremost ten feet of which are now embedded in a ridge of sea ice, as HMS Terror’s stern has been forced up by the ice pressure and the bow is pushed lower. Hickey is so lost in thought or cold that the caulker’s mate doesn’t notice his captain’s approach until Crozier joins him at a railing that has become an altar of ice and snow. The lookout’s shotgun is propped against that altar. No man wants to touch metal out here in the cold, not even through mittens.

Hickey starts slightly as Crozier leans close to him at the railing. Terror’s captain can’t see the twenty-six-year-old’s face, but a puff of his breath – instantly turning into a cloud of ice crystals reflecting the aurora – appears beyond the thick circle of the smaller man’s multiple comforters and Welsh wig.

Men traditionally don’t salute during the winter in the ice, not even the casual knuckling of the forehead an officer receives at sea, but the thick-clad Hickey does that odd little shuffle and shrug and head dip by which the men acknowledge their captain’s presence while outside. Because of the cold, the watches have been cut down from four hours to two – God knows, thinks Crozier, we have enough men for that on this overcrowded ship, even with the lookouts doubled – and he can tell just by Hickey’s slow movements that he’s half-frozen. As many times as he’s told the lookouts that they have to keep moving on deck – walk, run in place, jump up and down if they have to, all the while keeping their attention on the ice – they still tend to stand immobile for the majority of their watch, just as if they were in the South Seas wearing their tropical cotton and watching for mermaids.

“Captain.”