After being fired from his job at a grocer, George, gets a job as a stableboy at a local stud farm run by the Fleming family. He befriends the horse Hotspur who is a favourite to win the Melbourne Cup, and develops a strong whistle which is used to make the horse run fast.

Chic Williams (Pat Hanna) and his friend James Brown (Norman French) elude a private detective who's been following them, and head off to the bush (only later is it revealed that the detective wants to tell James he's inherited a fortune).