While Dora was pregnant with Marco, Carlo, an abusive heroin addict, was thought to have committed suicide at sea after his boat was found adrift.

With Bruno away as a commercial airline pilot, Dora is left all alone with Marco and only her shattered memory of the events of her former husband's death, caused by extensive electroshock treatment she received while institutionalized.

Wanting to save her from prison, Bruno hid Carlo's body in the house and released his boat to sea, staging his disappearance as a possible suicide.

In an abrupt but frenetic blind rage, Dora swings a pickaxe at Bruno, impaling him in the chest and subsequently stuffs his corpse in the open wall along with Carlo's.

[3] The script's original title was Al 33 di via Orologio fa sempre freddo ("It's always cold at 33 Clock Street"), and was loosely based on the novel The Shadow Guest by Hillary Waugh.

[3] Lamberto Bava would later return to the script and worked on it with Rabid Dogs co-writer Alessandro Parenzo, who was credited in the film as Paolo Brigenti.

[2] The musical score in the film was composed by the group Libra, with Carlo Pennisi on guitar, Alessandro Centofanti on keyboards, Dino Cappa on bass, and Walter Martino on drums.

[2][6] One of the film's promotional posters utilised artwork adapted (without credit) from William Teason's cover design for Popular Library's paperback edition of the Shirley Jackson novel We Have Always Lived in the Castle.

[8][9] Linda Gross of the Los Angeles Times deemed Shock a "slowly paced and silly tale of demonic possession", though she noted that "to Bava's credit, he uses more Oedipal implications than mechanical gimmickry".

[1] The review concluded that "The post-Exorcist possession crazy is now so burdened with inferior product that it is a pity that Bava's contribution should have been delayed in reaching Britain.

[1] From retrospective reviews, AllMovie called it "perhaps one of the more conventional offerings from a man whom many consider the founding father of Italian horror", though it "still bears the trademark style and technical trickery of Mario Bava's previous efforts".