Death Carries a Cane

Kitty, vacationing in Italy, uses coin-operated binoculars to scan the city and witnesses a woman being stabbed in her apartment by a killer in a black hat, glasses, and overcoat. She cannot get a clear view before the window scope runs out, forcing her to insert another coin to try again. In her scramble, she only notes the house number, a peanut vendor, and a cleaning woman on the street as the killer escapes.

Kitty shares what she saw with Alberto, and they decide to go to the police. They hope to trigger an investigation, despite Alberto's limp from an old injury.

An inspector visits and confirms that the first victim has been found, turning Kitty and Alberto's report into a real case. The danger feels immediate as word spreads of a killer on the loose.

Kitty recalls the killer walked with a cane, a detail that makes Alberto a suspect because of his injury, though he defends his innocence. The investigation begins to hinge on small, telltale imprints at each scene.

The peanut vendor is stalked to his home and slain by the killer who uses a cane to grab through the window and slit his throat with a straight razor. It is revealed that the vendor had blackmailed the killer about his identity, and his murder was meant to silence him.

After Alberto is cleared, the inspector tells him there was a second murder long before the most recent ones, and all the victims bear cane imprints connecting the cases.

The cleaning lady calls Alberto to her apartment, attempting to extort information about the killer. Alberto agrees to help, but she is killed later in her own home.

Alberto accompanies Marco to an audition for dancer Magda, who is managed by Marco's wife Lidia. Lidia has a twin sister, Silvia, which complicates the social circle around the case.

Magda returns to her hotel room to rest, where the killer is hiding under the bed and smothers her with a pillow. The act reveals the killer's willingness to act directly against the performers he targets.

To trap the killer under the assumption he's a maniac, Kitty poses as a prostitute to lure a client for a sting operation. A driver offers money and a cane clues, but the plan is scuttled when the police commissioner reveals himself, ending the sting prematurely.

A woman who saw the killer's face at a crime scene arrives at the Arrighi house, but flees after recognizing something in a photo. The killer then slips into her backseat, grabs her throat with the cane, and slashes her to death in her car.

Kitty and Alberto discover that Magda and the two earlier victims attended the same dance academy. A nighttime break-in uncovers records showing a familiar face, and the killer traps Alberto and a student in a closet. The pursuit ends with Kitty fleeing into a greenhouse as the inspector arrives and shoots the killer.

In a final revelation, a flashlight reveals the killer to be Marco. Lidia explains that Marco hunted the dancers who failed to please him and killed them in retaliation, using the cane as a red herring to throw the police off his trail.