John and Rae Ingram - the two characters who so fascinated readers of Aground - are alone on their honeymoon yacht in the mid-Pacific, when they are becalmed. It could have be idyllic. But they are soon forced to abandon any thoughts of solitary bliss.

Nearby, a ship is sinking. They rescue its lone passenger, a handsome young man, who claims he has had to bury his wife and another couple, dead from food poisoning.

But suspicion gnaws at Ingram. And in no time he and his wife are catapulted into a terrifying struggle for their lives.