After a warehouse on the Hudson River in New York is robbed, the police arrest Chico Brady and charge him with killing a worker when he tried to sound the alarm. A watchman at the building, in league with the thieves, confirms the accusation in order to protect Juan, the gang's leader. When Chico is sentenced to death for a crime he did not commit, his sister Nora does all in her power to prove his innocence, seeking help from Juan and, later, from the police who assign the case to detective Daniel Hogan, brother of the man killed. Posing as a gangster known as Frank "Scarface" Tunner, Hogan infiltrates the gang and finds the proof that reveals the real culprit. Chico's scheduled execution is halted at the last moment, and Dan and Nora make plans to start a new life together.