A young National Service deserter risks recapture to look after Sonny after he is injured in a rockslide.

As an amateur jockey, Mark is given the chance to ride Stormaway, Sir Adrian's best horse, in the Corinthian Handicap at Royal Randwick but when he goes missing before the race, Clancy secretly takes his place. Skippy places a $1 bet on a longshot, Wallaby Bill.

The animal and patrons of Waratah National Park run for cover when a bull gets loose and runs amok.

Sonny receives a steady stream of animal visitors while sick and confined to his bed. A home-made cold remedy may hold the answer — if Mark can get Sonny will take it — and if it's the right medicine.