Marianne is unhappily married with the rich Arvid Croneman. Arvid has been ill for some time and Marianne has been looking forward to his passing away. However, Arvid recovers. Marianne has had an affair with Lennart Hägg, her husband's doctor. She steals poison from his office and makes sure that her husband gets a poisonous injection that swiftly kills him. After his burial, Arvid's relatives, who lives in the house, treats her with suspicion. Has she really gotten rid of all the evidence?