Soon after the three Stryker brothers rob a train, killing someone in the process, Eliot Ness and his untouchables are on their trail. They get a warrant and seize the Strykers books and papers hoping to find something incriminating. The dim-witted Benny Striker has kept a piece of correspondence from the train robbery and his brothers decide they need to somehow get rid of that evidence. Benny approaches an old friend Mr. Jaeger, a retired arsonist, to set the Federal building's evidence room on fire and destroy the documents.