In the harsh winter of December 1889, the sailing vessel Irex leaves Scotland bound for Rio de Janeiro. She carries three thousand tons of pig iron and just three passengers for what should be a routine voyage. But Captain Will Hutton discovers that one of his passengers hides a horrifying secret. As his conflicting feelings toward his passengers threaten both his authority and even his sanity, he realises he must fight to save his ship.
When the Irex is wrecked off the Isle of Wight six weeks later, it falls to the county coroner, Frederick Blake, to begin to unravel the events that overtook the doomed ship — but he soon finds that powerful forces within the British Establishment are working to thwart him. Locked in a race against time and the sinister agents sent to impede him, he gradually discovers that nothing aboard the Irex is what it first seemed…