The storyline centres on the friendship between Mo, who is broke and behind in his rent, and Miriam, a young girl who claims to be an orphan, but who is in fact the runaway daughter of a rich aristocrat, Major Burnett. Mo is unaware that a large reward has been offered, but gangster Al Baloney and Mae West impersonator Kate plot to take the girl from him in order to get the money.
While Mo and his sidekick Donald undertake a series of disastrous attempts at finding employment, they inadvertently thwart the kidnap attempts. Miriam eventually leads Mo to the mansion where she lives but he is blamed for her disappearance and flees with Donald into the bush on a bicycle.
During their quest to find an old goldmine, the pair undertake various adventures, including being attacked by a tribe of Aborigines whom they take for cannibals. When they finally make it back to the city, they find that they have been cleared of any charges and the major throws a spectacular ball in Mo's honour.
A subplot involves a romance between a young couple, while the production itself includes a Busby Berkeley-style spectacle complete with 150 dancers.