Saint spots a nun wearing high-heeled shoes whilst collecting for charity at a London railway station, Simon's interest is aroused and he is soon plunged into an exciting cross-London chase to thwart the schemes of a clever gang of criminals.

Having rescued Liskard from death, Simon discovers that the man's enemies will stop at nothing to get their man. Liskard, the Prime Minister of a former British colony, it seems, is more vulnerable than most because he has political as well as personal enemies.