Television journalist Arlene Roskin comes from New York to interview Howard Bailey, a reclusive, retired television interviewer with particular interest in an interview he had with a former Mafia boss Abbalini, who squealed on his associates. Arlene is followed by a mystery man who robs her hotel room looking for that taped interview and efforts are made to blackmail Bailey into keeping quiet. Then Jim receives an interesting piece of news to suggest that Arlene is an impostor, who will do anything to get at Abbalini - but not for the reasons she is claiming.
Jim's date with new girlfriend, estate agent Susan Young, is interrupted when he is called in to investigate the death of young scuba driver Jacques Laval, whom the pathologist believes was murdered. Jim finds evidence that Jacques was smuggling in heroin with another diver. At the same time Moira Montauban, trophy wife of an arrogant French film star, disappears. When Jim catches up with her he finds she has made a new life for herself - but unfortunately, it is with the chief suspect.
Photographer Jerry Grant throws himself in front of a car and dies raving in hospital. Jim learns that he worked for a newspaper and had befriended Helene Duvall in order to gain entry to a black magic coven headed by occult writer Bart Bellow. Jim is initially sceptical, but when a neighbour of Bellow's dies mysteriously having released sacrificial animals, realises that he must take the matter very seriously. Helene offers to help but this places her in danger with Bellow and Jim must race to save her.
Looking for sunken treasure, the Deep Gold diving expedition makes the mistake of trying to scam crooked property developer B. J. Farrell into financing their supposed finds and end up having to leave Jersey. Jim, however, is more interested in why Farrell is visiting Miss Broome, a drunken recluse, with whom he would seem to have no connection. In fact she is his mother but she is being used by a rival of her son to draw him into a trap, which Jim must prevent.
Philippa Vale returns to the island to recover the stolen diamonds she hid underwater on her last visit, unaware that Jim had anticipated their hiding place and recovered them. Her presence attracts the arrival of a criminal gang and a bent copper, in whose capture Philippa ends up by assisting Jim.
A trio of young punks are snatching handbags around the island, their victims including fashion designers Simone and Paul Demoins, whose latest sketches are stolen. Louis, the least cold-hearted of the three robbers, befriends teenaged runaway Chrissie, who has come to Jersey to look for an aunt and who is the nanny to the Demoins' neglected little girl Michelle. Whilst Paul and Simone are in Paris, Chrissie and Michelle go on the run with Louis. Jim tracks them down but there is no happy ending.
When temperamental tennis star Rory O'Brien comes to play in Charlie's charity match, accompanied by manager McKennon and brother Frankie, Frankie asks Jim to give Rory police protection, shortly after which Rory is the victim of a hit-and-run. On the face of it somebody seems determined to stop him from taking part in the match but why are two shadowy men interested in a tennis racket Rory gave to Deborah, and how is a sweet old lady whose mother was a tennis champion innocently involved? Jim must find out.
Piggish German actor Henry Hoffman antagonizes everybody on set whilst making a film about Jersey's occupation by the Nazis, a fact which adds to local hostility and to the list of suspects when Hoffman receives death threats. Further complications are provided by the fact that Hoffman's father, a Wehrmacht soldier, was executed by firing squad during the war for raping a woman who is still alive and whose family may be seeking revenge. Thus when Hoffman is blown up at sea Jim is left with no end of potential murderers.
Jim feels exploited when MP Geoffrey Newton asks him to catch would-be assassin Mick Davies, who is threatening to disrupt the government's trade deal with Ahmed, a former terrorist who massacred Mick's Arab friends but is now a leading politician in his own Middle East country. Arms dealer Nigel Ripley, supplier of the guns for the massacre, also receives Mick's calling card, 'Avenge O Lord'. Jim encounters Mick, who spares him, but can a by-the-book cop outwit a seasoned commando?
Jim investigates when Charlie expresses concern at the influence supposed medium Raoul Barnaby has over elderly Mrs. Jardine with his story that he was contacted by the spirit of a little girl who died in a fire twenty years earlier. Jim finds that she was accidentally killed by Mrs. Jardine's son, who then committed suicide out of remorse but Plemont, the detective in charge, hushed matters up. After Mrs. Jardine has accused Barnaby of being a fraud, her niece Pauline, who is in league with Barnaby to rook the old lady, pushes her aunt downstairs. Following Mrs. ...