A very young Bernardo Bertolucci already shows his talent in this bleak, 94-minute murder mystery, told in an interesting series of flashbacks. A Roman prostitute has been brutally murdered in a park near the Tiber River and in order to forward their investigation, the police corner a handful of people who were in the park at the time. As they separately tell their versions of why they were there and what they did, their narrations do not necessarily match the images on the screen that do reflect the truth. By the time all the flashbacks have been completed, a real picture of the crime emerges, revealing that one of those in custody is the killer.