
A rich widow is found dead in her apartment in Helsinki due to gas poisoning. The incident is initially thought to be an accident, but inspector Palmu notices that the murderer made a mistake, and so Palmu, Kokki and Virta begin the investigation: who had come to the apartment through the balcony door and opened the gas tap while Mrs. Skrof was asleep?
Palmu

Toivo Virta
Väinö Kokki

Kirsti Skrof

Kurt Kuurna

Kaarlo Lankela

Mustapää

Alma Skrof

Iiri Salmia
Lanne

Doctor

Hallamaa
Anna

Ara

Hakanen
Janitor's Wife
Janitor

Leppä

Vesa
Pihlaja

Pentti Lanne
Cleaner

Postman

Homicide Detective
Homicide Detective
Waitress
Butler
Drunk

Police Officer
Young Man in Metropol

Mrs. Lanne
Domestic Worker
Homicide Detective (uncredited)

Young Kirsti Skrof (uncredited)
Postal Worker (uncredited)
Young Woman in Metropol (uncredited)
Man Holding Kuurna (uncredited)
Dancer (uncredited)
Man in Lineup (uncredited)