Three couples are involved in a murder at Montecarlo.
Alberto Sordi
Alberto Franzetti
Vittorio Gassman
Remo
Nino Manfredi
Quirino
Dorian Gray
Eleonora Franzetti
Franca Valeri
Giovanna
Georges Rivière
Eleonora's Lover
Bernard Blier
Commissario Polizia
Silvana Mangano
Marina
Sylva Koscina
Carolina
Giulio Tomasini
Giambattista
