For 1963’s landmark The Girl Who Knew Too Much, Italian horror legend Mario Bava is credited with pioneering the giallo film, one of the most influential horror subgenres. But with 1971’s A Bay of Blood, Bava mixed the giallo film’s black-gloved point-of-view killers and highly stylized murder scenes with the body count framework of Agatha Christie’s And Then There Were None to create an even further-reaching subgenre: the slasher film.
A Bay of Blood (which is also known by a wide variety of alternate titles; Chain Reaction, The Ecology of Crime, and my personal favorite, Twitch of the Death Nerve) features one of the best opening scenes in the giallo canon. After some introductory establishing shots of the titular bay, we see a lonely countess in a wheelchair slowly meandering around her waterfront mansion. Through a trademark giallo point-of-view shot, we witness a black-gloved killer throw a noose around her neck and kick her wheelchair out from under her: a typical but impeccably stylish beginning for a giallo. After her death, Bava throws us a curveball. Rather than serving as the expected setup for a whodunit, the camera pans up from those black leather gloves to reveal the killer’s face. Just as the killer begins staging the crime scene, setting out a forged suicide note, a second killer appears and stabs him to death.