In this, the fourth and final book in his Septimus Treloar series, Stephen Chance takes the reader back to the early days of the endearing policeman-turned-parson's career, to fill his fans in on the story of Septimus's life as a young man. The setting is World War II, and Septimus has been summoned to handle a very delicate and important assignment. The details of a top secret radar device, code name H2S, have fallen into enemy hands. His mission to discover the cause of the leak removes him from the familiar world of 'honest' crime, and entangles him in the subtle and dangerous workings of wartime counter-espionage.

Before long he is chasing spies, hunting down traitors and crossing international borders in Stephen Chance's exciting and witty thriller. First published in 1979, Septimus and the Spy Ring is a brilliant send off to one of the most eccentric and charming heroes of all young adult fiction.