A parody of old gangster movies set in the corrupt Chicago environment of Prohibition (1930). The citizens of Cheesecago are defenseless against the control of the gangster Alcatone. Only a group of brave agents led by Elliot Mouse dare to confront the "catsters" and try to stop the evil plans of Alcatone. All this takes place in an atmosphere of humor and without violence as we follow the adventures of our four heroes against tough guys, corruption, robberies, car chases...