Twelve year old Stuart is desperate to get into motor racing, but his family are not wealthy and it seems a vain hope. However his uncle has put some money aside for driving lessons, so Stuart gets to drive karts. Showing early promise Stuart’s main rival is Sidney, for whom money is no object, but Stuart has some lucky breaks and some unlucky ones, such as his collar bone. Finally a secret sponsor comes forward so the battle between Stuart and Sidney goes to the final. But who was the secret sponsor?