"Nove Ospiti per un Delitto" is 血手淫心a mediocre giallo in the tradition of Agatha Christie's "And Then They Were None". Nine members of the same family go to an island, where nobody lives - but the head of the family (Arthur Kennedy) owns a nice house there. Problem is that he and his three sons keep a dark secret, and this dark secret begins to haunt them as soon as they are on the island. One by one they fall victim to a mysterious killer... (IMDb)