A Bay of Blood

A Bay of Blood (Italian: Ecologia del delitto, lit. 'Ecology of Crime', later retitled Reazione a catena, 'Chain Reaction'; also known as Carnage, Twitch of the Death Nerve and Blood Bath) is a 1971 Italian giallo film directed and co-written by Mario Bava and starring Claudine Auger, Luigi Pistilli, Claudio Camaso, Laura Betti, Leopoldo Trieste, Anna Maria Rosati, Brigitte Skay, Chris Avram and Isa Miranda. The story details a string of mysterious murders that occur around the titular bay.

Widely considered Bava's most violent film, its emphasis on bloody murder set pieces, created by effects artist Carlo Rambaldi, was hugely influential on the slasher film subgenre that followed a decade later. In 2005, the magazine Total Film named A Bay of Blood one of the 50 greatest horror films of all time.