English eccentric Barrington Shakeshaft has retired from a colourful life of swashbuckling adventure to live in a caravan in the paddock of his daughter's home in Sussex. He amuses himself by perpetrating benign hoaxes on gullible journalists and duping greedy art dealers with forged paintings done in the style of famous painters.
When police announce a fresh appeal for witnesses on the first anniversary of the unsolved murder of a schoolboy, Shakeshaft decides to telephone a newspaper claiming to be the killer. But when he reveals the plan to Logan Hunter, chief crime correspondent of a Sunday newspaper, the journalist points out to him the foolishness of such an action and the effect the false claim would have on the bereaved parents.
Filled with remorse at his own stupidity, Shakeshaft sets out to find the killer himself.
The extraordinary investigation which follows breaches all the rules and accepted conventions of normal police work. He devises imaginative and bizarre methods of acquiring and examining forensic clues and draws on the experience of daring escapades and dubious enterprises he engaged in as a younger man to trick witnesses into telling him more than they should.
Shakeshaft teams up with Hunter and their inquiries lead them into the murky world of a sinister secret society, which practises the ritual abuse of young boys.
With the grudging co-operation, but often bitter opposition, of Detective Chief Inspector Paddy O'Shaughnessy - the policeman in charge of the murder investigation - they solve the crime. Or do they? There is an intriguing twist at the end of this tale. This is an old-fashioned whodunit with a distinctly modern flavour.