Ran decides to phone her father to ask for help, but he is busy playing Mahjong. Later Eri realizes that a tape recording was used to create the alibi of her husband. The wife then reveals that her husband cheated on her with a friend's wife, but Eri revealed he did so because he was jealous that his wife was inlove with the husband of the women he was cheating on. Later, Conan finds out Mouri indirectly helped his wife solve the case.

A person who murders people with a hammer dubbed "Hammer Man" has be spotted after a murder heading to an apartment. Sato and Takagi stalk out the apartment. After realizing there was no activity in the apartment, they enter the suite and find a man who's hanged himself. They then realize that the man who hanged himself is not the hammer man and that the culprit has impersonated a delivery worker and escaped.