While visiting St. Joseph, Missouri to see his former girlfriend, an up-and-coming soprano, Bat comes to the aid of a businessman who refuses to pay protection money but finds himself accused of being an enforcer for the racket.

When Bat buys a derby hat in a small Missouri town he is aghast at the price. Learning that a freight line owner forces shopkeepers to use only his line to ship their supplies from the river, Bat decides to break his monopoly.