Inspector Ronald Dobbs of Scotland Yard thought the Mediterranean cruise would be a good rest from fighting crime. And the shipboard masquerade ball was a good way to relax and have fun. But the mask of one of the revelers hid the face of a cunning murderer. And when a corpse in a fancy costume turned up, the party's festive air of make-believe was shattered by the grim reality of death. Suddenly the inspector's dream vacation had turned into a nightmare!