Nell McDermot is devastated when the cabin cruiser of her husband, architect Adam Cauliff, blows up with him and three others on board. As the investigation into the boat's explosion proceeds, she learns that it was not an accident but a bomb.
The last time she saw Adam, they had a bitter quarrel over her plan to embark on a political career. Wracked with guilt over her last harsh words to Adam, she overcomes her scepticism and responds to a message from a medium claiming to be his channel.
While trying to unravel the threads of Adam's past and his violent end, Nell continues to see the medium, who transmits messages to her with instructions from Adam. The story reaches a powerful climax in Nell's final encounter with the medium, in which she learns the truth about the explosion - a truth she can't be allowed to live and tell . . .