Though he's at the bottom in the line of heirs - ninth, in fact - to take possession of the D'Ascoyne family fortune, poor relation Louis Mazzini (Dennis Price) sets out to bump off the other eight heirs ahead of him, including an arrogant playboy, a formidable dowager, a stiff-upper-lipped admiral, a fussy reverend and four more, all played by the brilliant Alec Guinness, long before his Obi-Wan Kenobi days.