Sam and Molly are a very happy couple and deeply in love. Walking back to their new apartment after a night out at the theatre, they encounter a thief in a dark alley, and Sam is murdered. He finds himself trapped as a ghost and realises that his death was no accident. He must warn Molly about the danger that she is in. But as a ghost he can not be seen or heard by the living, and so he tries to communicate with Molly through Oda Mae Brown, a psychic who didn't even realise that her powers were...

The polar ice caps have melted, and the earth is covered by water. The remaining people travel the seas, in search of survival. Several different societies exist. The Mariner falls from his customary and solitary existence into having to care for a woman and a young girl while being pursued by the evil forces of the Deacon.