Detective Inspector Montague Pluke, of CID, is England's most superstitious police officer. With crime at its lowest level for years, he decides to conduct a cold-case review. But there are no major unsolved crimes so, alerted by his wife, Millicent, to a large number of recent deaths - his expert knowledge of superstitions and folklore lead him to justify re-opening a case. Could an undetected mass-murderer be operating in Crickledale?