Mr. North is the manager of the traveling circus to which Richy the Amazing Boy is attached as an actor and performer. Richy brings Rang-a-Tang and Detective Speed with him to tour with the performance.
Mike Vincent approaches Mr. North with a proposal to protect the circus with his gang of thugs. When Mr. North refuses,Vincent’s gang releases Mamothia, the ‘largest captive gorilla in the world’, to threaten the crowds and cause chaos for the entertainers. Rang and the gang put a quit to the nefarious plot.