
Eight-year-old Roger Court is in Venice expecting to reunite with his father, British diplomat Major Court (Trevor Howard), whom he hasn't seen in three years. Roger lives with his Aunt Rose since his mother abandoned him.

Richard O'Sullivan
Roger Court

Alida Valli
Roberta Gleukovitch

Eduardo Ciannelli
Dr. Vivaldi

Trevor Howard
Major Roger Court

Richard Basehart
Joe Hamstringer

Stephen Murray
British Consul in Venice

Arnoldo Foà
Commissioner

Guido Celano
Chief Constable

Helen Goss
Undetermined Role
Giorgio Costantini
Pescovitch
Angelo Cecchelin
Luza
Nino Vechina
First Killer
Armando Papette
Second Killer
Giovanni Karuz
Third Killer
Joan Butterfield
Mrs. Harrington