The ultimate puzzle movie, this underrated gem will keep you guessing until the very end - and maybe even after that! Producer James Coburn throws a party on his yacht for his friends and enemies: a struggling screenwriter (Richard Benjamin) and his rich wife (Joan Hackett), a down-at-his-heels former A-list director (James Mason), a fading starlet (Raquel Welch), her gigolo boyfriend (Ian McShane) and an acid-tongued agent (Dyan Cannon). But murder is afoot.