The plot involves the murder of a world-famous individual on Combe, a secluded island off the Cornish coast in England. The investigators are Commander Adam Dalgleish and his team, Detective Inspector Kate Miskin and Sergeant Francis Benton-Smith. The detectives are confronted with a "closed island mystery," since access to Combe is limited to a few invited guests. It would be almost impossible for an intruder to sneak onto Combe and kill someone unnoticed. Which one of the residents had the motive, opportunity, and strength to strangle the victim and hang him from a lighthouse railing?