One of four films directed for Italian TV by Lamberto Bava, as part of the Brivido Giallo series, PER SEMPRE (re-titled UNTIL DEATH in the version I saw) concerns a man's love and hate coming back from the grave to haunt a woman, her lover, and her son.
A pregnant Linda (Gioia Scola) and Carlo (David Brandon) poison her unpleasant, booze-loving husband Luca. Before they successfully bury him in a shallow grave, though, he pops to wakefulness and tears an earring from Linda's ear. Carlo beats him to death and they cover his grave.
Six years later, Linda is still just making ends meet running a lakeside restaurant. Her relationship with Carlo grew abusive years before, and her son (Marco Vivio) has nightmares in which his father's rotted corpse torments him and enters his bedroom through the wall.
Enter Marco (Urbano Barberini), a drifter who stays one rainy night and never leaves. Marco helps Linda run the restaurant, but Carlo suspects he's a cop, and even Linda grows wary when he gives her the missing earring that Luca took to the grave. Meanwhile, her son and Marco grow closer.
Carlo and Linda finally re-open Luca's grave, only to find his decayed body and no sign of the earring. Their situation goes quickly downhill from there, as it becomes clear that Marco is some sort of reincarnation of the dead husband. The movie's underlying themes -- which cover adultery, betrayal of love, and retribution for acts of sin -- are handled with a caustic, mean-spirited tone.
The story's reason for being can be summed up in Marco's admonishment to Linda in the exciting climax, "You cannot escape your own sin! You must pay!" Around the same time, Bava treats us to an absolutely skin-crawling scene in which Marco and Luca "merge" to form one man with two faces.