A family's murderous battle over some bayfront property is the subject of director Mario Bava's bloody horror-thriller, which many have cited as the grandfather of the modern slasher film. Claudine Auger is the scheming daughter of a murdered Countess; her staged suicide forms the basis of the film's plot. In a seemingly unrelated subplot, four hippies arrive in a dune buggy led by Brigitte Skay, who dances the Shake and swims naked before having her throat hacked open with a machete. Skay's boyfriend has his face chopped with the same machete and the other couple has a spear thrust through their bodies as they make love. All of these murder scenes were imitated in Steve Miner's Friday the 13th, Part 2, and the film's style influenced countless American slasher films of the 1970s and '80s. Bava also includes a strangulation by telephone cord, a gory axe decapitation, a man speared to a wall, and five other murders. Antefatto was a trendsetting film, and paved the way for literally hundreds of graphically violent imitations. The film exists in several versions, differing mainly in the extent of the bloodshed.