The Psychotronic Film Society’s long-running weekly series of obscure or underappreciated feature films from around the globe continues with a rare public screening of a forgotten gem. “Venom” is a British-made thriller from 1981 starring Oliver Reed (“Tommy”), Sarah Miles (“The Sailor Who Fell from Grace with the Sea”), Klaus Kinski (“Nosferatu”), Nicol Williamson (“Excalibur”) and Susan George (“Straw Dogs”).

It’s the taut tale of a child kidnapping gone wrong that evolves into something much more treacherous, when an extremely poisonous and highly aggressive African Black Mamba snake gets loose in the house during the crime. Before long, the police have surrounded the house, trapping the criminals and the young boy inside with the deadly animal.

“Venom” was originally set to be directed by Tobe Hooper (“The Texas Chainsaw Massacre,” “Poltergeist”), but he left just a couple of weeks into shooting over creative differences with the producers. He was replaced by Piers Haggard, who’d previously directed the cult classic of occult horror “The Blood on Satan’s Claw” and a 1979 adaptation of the adored British sci-fi TV serial “Quatermass”).

The finished film received mixed reviews on initial release, but has acquired a devoted cult following since, as it’s hard to tell whether the film is surprisingly good or surprisingly bad. It seems to hover somewhere in between at all times, while never failing to be anything other than quite entertaining to most viewers. Showtime at 8 p.m., with a full, award-winning vegetarian menu available and discounts on craft beer and organic wine during the film.