Tophaneli Osman.

Before his death, Esad Bey decides to announce his will. He calls all his relatives to his house. He leaves most of his inheritance to his stepson Murat and the rest to his relatives. Shortly thereafter, Esad Bey is murdered. Murat is framed for the crime and sent to prison. Murat, who is innocent, will discover the identity of the killer thanks to Tophaneli Osman, whom he meets in prison.