The Big City is an improbable urban melodrama which takes place during a "taxi war" between honest independent cabdrivers and graft-ridden taxi monopolies. Looking for a scapegoat for a recent gangland bombing, crooked city officials deport the foreign wife (Luise Rainer) of rabble-rousing cabbie Spencer Tracy. Desperately seeking a reprieve for his wife, Tracy goes to the mayor, who is in the process of addressing a banquet of retired boxers. The ex-pugilists take Tracy's side, head down to the wharf to pummel the gangsters responsible for the bombing, and rescue Tracy's wife from being shipped back to her homeland.