The quiet town of Cattminster is shocked by news of a startling murder - startling because all the evidence points to the murderer being Richard Groom, grandson of the late canon of Cattminster Cathedral and ex-fiancé of the victim's wife.

Richard, however, has five stout allies who believe unquestionably in his innocence. With the one idea in common, but with their own individual ideas on how to set about it, they go to work to prove his innocence - with surprising results.