Ben Kitto now the Scilly Isles' Deputy Chief of Police is missing the excitement of the murder squad in London. But when the body of professional diver Jude Trellon is discovered anchored to the rocks of a nearby cave his investigative skills are soon needed. Jude's death looks like a tragic accident but when evidence is found that suggests otherwise the islanders close ranks. With even those closest to the victim refusing to talk it seems that plenty of people might have wanted to harm her. Kitto suspects a killer is on the loose in Tresco - and nobody is safe...