George Shuttleworth is convinced that he has the talent to win the Isle of Man TT races, despite what his neighbours back home in Wigan may think. During the trials, the brakes go on George's bike, 'The Shuttleworth Snap', which he made himself. As a result, he breaks the TT lap record, becoming an instant motor-cycling star. As the big race approaches, George soon realises that other jealous riders will stop at nothing to make sure he does not take part in the race. An early George Formby film and probably his best.

A series of unexplainable accidents befall the people and companies responsible for developing the world's first supersonic airliner (SST1). A British agent is sent to investigate and with the help of another agent uncovers a plot masterminded by Carl Petersen who stands to gain eight million pounds if the aircraft is not ready by a certain date. The evil Petersen has developed a number of "robots" (actually rather beautiful girls with "electronic brains") to help him sabotage the SST1 project by means of "infrasound" (extreme low frequency sound waves) which can be directed at people or objects with devastating results.