Deep Red (original title Profondo rosso; also known as The Hatchet Murders) is a 1975 Italian giallo film, directed by Dario Argento and co-written by Argento and Bernardino Zapponi. It was released on 7 March 1975. It was produced by Claudio and Salvatore Argento, and the film's score was composed and performed by Goblin. It stars David Hemmings as a music teacher who investigates a series of murders performed by a mysterious figure wielding a hatchet.
Although the film was not a financial success internationally, it met with critical acclaim and is the most well-known giallo film to date.
Plot: The film follows music teacher Marcus Daly (Hemmings) as he investigates the violent murder of psychic medium Helga Ulmann (Macha Meril), which he witnesses in an apartment building. Other major characters are introduced early, including Daly's friend Carlo (Gabriele Lavia), Ulmann's associate Dr. Giordani (Glauco Mauri) and reporter Gianna Brezzi (Daria Nicolodi), with whom Daly begins an affair.After his attempt to rescue the medium fails, Daly realizes he has seen a certain painting among a group of portraits on the wall of the victim's apartment, but it seems to have disappeared when the police arrive. Later in the film, he also initially overlooks another clue that causes him to discover a mouldering corpse walled up in a derelict house. One murder leads to a series of others as Daly's obsession with this vital clue that he fails to understand endangers his life and that of everyone with whom he comes into contact. Among those killed are Giordani, Amanda Righetti (Giuliana Calandra) and Carlo. The killing of Helga Ulmann is prefaced by a child's doggerel tune, the same music that accompanies the film's opening sequence in which two shadowy figures struggle until one of them is stabbed to death. The music serves as the murderer's calling card. When Daly hears it in his own apartment soon after becoming involved in the case he is able to foil his attacker. Later, he plays the tune to Giordani, a psychiatrist, who theorizes that the music is important because it probably played an integral part in a traumatic event in the killer's past. The doctor's theory is of course correct, as the identity of the killer is finally revealed as Carlo's insane mother Martha (Clara Calamai). When Carlo was still a child, he watched as she murdered her husband when he tried to have her committed to a mental hospital, then entomb his body in a room of their house. Daly's discovery of the corpse is one of the film's most dramatic moments.