Kitty, a photographer living in Rome, accidentally witnesses the murder of a young woman at the hands of a razor-wielding black-gloved killer. Kitty and her fiance Alberto go to the police only to learn that two other witnesses to the crime have been slashed to death. Kitty fears that she will be the next victim when her ballerina friend Magda is brutally killed by the same elusive culprit.

The police are baffled and are unable to find a motive. It is Alberto who discovers the connection: all the murdered girls were dancers…