Spring 1894
Private detective Jane Dowling is invited by a client to join her eccentric family on a cruise down the Amalfi Coast of Italy. This cruise has been arranged on instruction by the family lawyer, five years after the death of her father. The intention being to decide how his inheritance is to be divided, by an elaborate evaluation of the main family members.
However, the cruise is plagued with a series of apparent accidents, and bad weather forces them to change route and visit some dangerous islands. It is not clear if the threat to the family is coming from inside or outside.
Jane is helped at first by a nervous young legal assistant, then after his death, by a charismatic, Italian police inspector. As the cruise continues down the coast to Pompeii, the secret purpose of the cruise is revealed, but the situation in Italy has worsened since the old man's death and the family face a new threat from which Jane has to help them escape.