Catherine Marshall is a pretty young woman who comes to see about rogue racing car team owner Oscar Newley (Eddie Byrne.) He stole his father's fuel injection system that could revolutionise sports car racing.
Only Oscar is down in his luck. He has a reputation of a man who is jinxed. He is heavily in debt and someone has purchased his debts and turning the screws on him.
Oscar suspects rich playboy Beau Ellington to behind his misfortune. He is after Oscar's patent for the fuel injection system.
The Saint introduces himself as a potential investor and wants to see the fuel injection system in action. Only at each turn, Oscar's car is sabotaged.
One night Oscar's garage is burnt down and Simon Templar has to rescue Oscar from the burning garage. As always the main suspect is Beau but he pleads his innocence.
There is a good mystery here once Oscar realises that his loyal mechanic is not that loyal. Beau claims he fights fair when it comes to motor racing.
Oscar is not quiet the villain he is painted to be. The Saint likes him and wants to help him beat the fat cats.