It follows Francesco Koch (Kieran Canter), an orphaned taxidermist who inherits a house in the woods where he lives with his housekeeper Iris (Franca Stoppi), who is determined to become the new owner.

After Iris kills his girlfriend Anna (Cinzia Monreale) with a voodoo curse, Francesco steals her corpse from the local cemetery.

A local undertaker (Sam Modesto) investigates and meets Teodora (also Monreale), Anna's twin sister.

Since his parents died in a car accident nine years before, the affluent Francesco Koch[N 1] has been living with his wet nurse and housekeeper Iris in a villa at the outskirts of a South Tyrolian town.

Wanting to marry Francesco and become the new lady of the house, Iris hires a witch to curse his fiancée, Anna.

The funeral is attended by Francesco, Anna's parents and her twin sister Teodora, who studies at a nearby school.

Assisted by Francesco, Iris chops up the hitchhiker's corpse and dissolves the pieces in a bathtub filled with acid, then disposes of the liquid in a hole in the garden.

When Iris threatens to dispose of Anna's body, Francesco gives in and offers to marry her and make her mistress of the house.

The following day, while Iris is drunk and Francesco is out for a jog, the mortician enters the house to investigate, discovers Anna's body, photographs it and leaves.

When the mortician returns, he finds Iris' corpse and Francesco badly injured near the furnace burning with human remains.

As Francesco collapses and dies, the mortician takes Teodora, whom he thinks to be Anna's corpse, returns to the cemetery and places her in a coffin for burial.

[4] The film was shot in two weeks in South Tyrol province, in the towns of Brixen and Sand in Taufers, in late June and early July 1979.

"[4] D'Amato said in an interview "I personally opted for the most unrestrained gore, since I don't consider myself very skillful at creating suspense....It's my most successful horror movie, and still stands out today above many others of its kind.

"[5][6] The special effects for the gore scenes in the film were made by using animal intestines, pig skin and a sheep's heart which were provided by an abattoir.

[8] From retrospective reviews, in his 2001 book reviewing gory horror films from the decade, Scott Aaron Stine declared that Beyond the Darkness was D'Amato's "strongest contributions to the [horror] genre", while still finding the film to be "cheap Italian trash [...] but it approaches the subject with a certain amount of flair not found in similar productions.