Eight years ago, HMS Melpomene met disaster on her search for the missing Franklin polar expedition. A tiny handful of survivors returned home against all odds; now, one of them is to be hanged for the murder of his wife and brother, a crime he claims no memory of committing.

Among the spectators is ambitious London newsman, Harry Lambert, obsessed by the Melpomene story and the question of what could drive a hero of the Arctic to such an end.

His search for answers takes him to the door of Sidney Blakely, the survivors' charismatic leader turned celebrated Spiritualist medium - a power granted to him, he says, in the thin-veiled North. Living with him is Lieutenant Taylor who claims a darker 'gift': to be a vessel for possession by spirits of the dead. Harry doesn't believe a word of it. But as the true, bloody story behind Melpomene's end unfolds, he begins to wonder.

Blakely's revelations of desperate mutiny and a hierarchy out of its depth are shocking enough. But between these lines are whispers of unquiet ghosts, and more than ordinarily savage beasts. In the gaps between what is said and unsaid, what can be believed is as shifting and unstable as the ice itself.

Harry knows what Melpomene's crew left in the Arctic. But what did they bring back?