A police captain poses as the valet of a friend who has been invited on a yacht cruise by a notorious schemer, whom the friend is afraid wants to murder him.
Capt. Roger Peel
Sylvia Paget
Vernon Wolfe
Captain MacDonnell
Arthur Wardell
Count Boris Ivanoff
Dr. Saunders
Countess Olga Karova
Nigel Menzies
Colonel Paget
Lisette - Maid