The murder of a wealthy heiress by her husband triggers a series of brutal killings in the surrounding bay area.
A Bay of Blood (Italian: Ecologia del delitto, lit. "Ecology of Crime", later released as Reazione a catena [lit. "Chain Reaction"] and Bahia de Sangre [lit. "Bay of Blood"]), also known as Carnage, Twitch of the Death Nerve and Blood Bath, is a 1971 Italian horror film directed by Mario Bava. Bava co-wrote the screenplay with Giuseppe Zaccariello, Filippo Ottoni, and Sergio Canevari, with story credit given to Dardano Sacchetti and Franco Barberi. The film stars Claudine Auger, Luigi Pistilli, Brigitte Skay, Nicoletta Elmi and Laura Betti. Carlo Rambaldi created the gruesome special make-up effects. The story details the simultaneous murderous activities of several different characters as they each attempt to remove any human obstacles that stand in the way of an inheritance of a bay.
Widely considered Bava's most violent film, its emphasis on graphically bloody murder set pieces was hugely influential on the slasher film subgenre that would follow a decade later. In 2005, the magazine Total Film named A Bay of Blood one of the 50-greatest horror films of all time.