In New York City, for the past several weeks, a rampaging homicidal maniac has been targeting young girls belonging to all walks of life. No ties apparently bind the victims together....
As the Police investigation focuses on a suspicious individual involved in prostitution circles, the killer continues to rage with ferocity and, after killing a young bicyclist and a nymphomaniac who had accompanied the investigated gigolo, targets young Kitty, mistress of the Lieutenant in charge of the investigation, Williams, and subjects her to a heinous torture perpetrated with a razor blade.
And as the trail of bloodshed continues, a young graduate student and his beautiful fiancée find themselves caught up in the chain of crimes.
The murderer, before he strikes, boasts of his actions by phoning the Police and altering his voice, giving it the tone of "duck": this clue leads one of the chosen victims, after the chance discovery of some documents, near a Hospital, inside which is concealed the motive of the brutal murderer.
Fulci does not compromise, and in addition to filming death in its most revolting aspects, he shows sequences of rather raunchy eroticism (Alexandra Delli Colli being bothered in a bar, and then in bed with the gigolo).
Anthology-like is the building of suspense, made almost total at the moment when one of the victims, while listening to the radio focuses, based on the sketch circulated by the speaker, in the lover the possible killer.
In addition to Fulci's usual fleeting appearance, the presence of Paolo Malco (now a TV drama performer) and Andrea Occhipinti (later also an actor in the similar La casa con la scala nel buio, directed by Lamberto Bava) should be noted.
The killer's first victim was Cinzia De Ponti, then a star in some television variety shows.
The screenplay, originally by Clerici and Mannino, was reworked by Dardano Sacchetti, and the original subject was later turned into Deodato's film Un delitto poco comune (1987).
