The men on board Her Britannic Majesty's Ships Terror and Erebus had every expectation of triumph. They were part of Sir John Franklin's 1845 expedition - as scientifically advanced an enterprise as had ever set forth - and theirs were the first steam-driven vessels to go in search of the fabled North-West Passage.

But the ships have now been trapped in the Arctic ice for nearly two years. Coal and provisions are running low. Yet the real threat isn't the constantly shifting landscape of white or the flesh-numbing temperatures, dwindling supplies or the vessels being slowly crushed by the unyielding grip of the frozen ocean.

No, the real threat is far more terrifying. There is something out there that haunts the frigid darkness, which stalks the ships, snatching one man at a time - mutilating, devouring. A nameless thing, at once nowhere and everywhere, this terror has become the expedition's nemesis.

When Franklin meets a terrible death, it falls to Captain Francis Crozier of HMS Terror to take command and lead the remaining crew on a last, desperate attempt to flee south across the ice. With them travels an Eskimo woman who cannot speak. She may be the key to survival - or the harbinger of their deaths. And as scurvy, starvation and madness take their toll, as the Terror on the ice become evermore bold, Crozier and his men begin to fear there is no escape...