When the Saint signs on as a mercenary, and finds that things are none too healthy on the health farm where he's being trained, he decides to find out the real function of the establishment. Is it a school for murder?

The Saint finds himself playing a deadly game of cat and mouse with a would-be killer. Simon's dilemma is twofold: why should anyone want to put a dent in his halo and who is the man known only as 'The Avenger'?