‘Diabolical. Fiendish. Savage.’ So promises the radio spot for Mario Bava’s seminal slasher. The perverse endorsement goes on to warn, ‘You may not walk away from this one’. Although you are in fact very likely to survive the film’s duration, A Bay of Blood prides itself on being an onslaught of escalating mayhem. It reveals murderer after murderer - and, as an experience, is something of a hysterical, even baffling ordeal.

Conceived as a commentary on the 1968 worldwide student protests - which pitched younger generation against older - it opens thrillingly as the elderly Countess Federica (Isa Miranda) manoeuvres her wheelchair around her plush property, accompanied by rising orchestral strains. Suddenly, an unseen assassin appears, tipping Federica from her chair and stringing her up with mechanical malice. The murderer is revealed as her husband Count Filippo Donati (Giovanni Nuvoletti). However, in a further delicious twist, consistent with the film’s cut-throat, irreverent approach, Filippo himself is instantly dispatched by a mystery assailant, stabbed repeatedly before falling under the swinging, lifeless hands of his own victim.

Unfortunately, there’s nothing else in the ensuing film that quite matches this operatic, visually striking opener, with the rest of the picture a more conspicuously low-budget affair. However, A Bay of Blood compensates for its ragged appearance with bravura camerawork and a number of witty death sequences: a couple are killed with a spear as they make love, a skinny-dipper is molested by a corpse, and a drowned man is dramatically revealed with an octopus slithering across his face. Special mention here must go to Carlo Rambaldi for his gruesome and ingenious effects work.

A Bay of Blood is renowned for its multiple titles, high body count and considerable, if inauspicious, legacy. Known variously as Carnage, Blood Bath and - in a bizarre rebranding - Last House on the Left - Part II, it is also still remembered by the most evocative of these alternative monikers, Twitch of the Death Nerve. A Bay of Blood might not be its most imaginative title but it is at least the most apposite, as its convoluted narrative concerns a violent wrangle over the inheritance of a bay, with various parties, including Renata (Claudine Auger) and her stepbrother Simon (Claudio Volonté) fighting over ownership. It features a whopping 13 murders in total - an impressive and appropriately unlucky number.

Its most obvious imitator is the Friday the 13th series but, interestingly, A Bay of Blood‘s hapless young quartet survive only 10 minutes of reckless revelry before they are picked off by the killer. What Bava barely even regards as a sub-plot would form the basis for an entire franchise and its own numerous imitators.

A Bay of Blood lacks the consistent compositional brilliance of Bava’s best work (for example Mask of Satan) and time has not been tremendously kind; however, it has its charm. As the victims pile high and killers greedily compete, it gleefully erodes your faith in humanity, before smashing it with a sledgehammer in a cruel yet wonderfully daring punchline.

Emma Simmonds