When unassuming clerk Tom Blake (Conrad Nagel) is framed with the murder of a policeman in the midst of a violent bank robbery, the innocent pawn briefly eludes the authorities before committing suicide. Arriving at the scene just as Tom breathes his final breath, twin brother Ralph vows to avenge his the death of his ill-fated brother after reading a letter detailing his innocence. In turn mistaken for Tom by a gangster (George Stone) who arrives at the scene shortly thereafter, Ralph learns of a nefarious figure known as "The Bat" (William Russel) who carries out the biddings of underworld kingpin "The Chief." Soon mistaken for his brother by the police as well, Ralph hides out in the apartment of the slain police officer's daughter Slinkey (Myrna Loy), quickly forming a romantic bond and partnership with the girl in order to seek out "The Bat." Soon realizing that "The Bat" and "The Chief" are one in the same, Ralph pursues the vicious killer onto a nearby rooftop with the police in hot pursuit. Derived from a story by Melville Crossman, in addition to being the first speaking role for actress Loy this film took advantage of the recent advent of film sound to include two scenes of key exposition.
by Jason Buchanan synopsis