Reazione a Catena (also known as
Bay Of Blood,
Twitch Of The Death Nerve,
Ecologia Del Delitto...) is a 1971 horror film by Mario Bava. Designed as a comeback film after he lost his distribution deal with American International Pictures, Bava effectively created a film that has served as the blueprint for the Bodycount/Slasher genre of horror, with many of its sequences copied by other horror films (most notably
Friday The 13th)
The film's plot is a convoluted "
Who Done It", as people begin dying left and right during the course of a long weekend at the lakeside home of an elderly heiress. There are multiple murderers at work, as a slew of shady characters (and a quartet of sex-obsessed teens) end up dying in horrific fashion. There is also a
Surprise Ending that will shock you...
This film provides examples of: