A U.S. Senator is found brutally murdered with a machete on the grounds of an exclusive golf club on one of the British Seaward Islands. John and Margaret Colville, who operate a modest hotel on the island, ask their friends Chief Superintendent Henry Tibbett and his wife, Emmy to come to St. Mathews' to conduct an investigation. Although an amiable young islander who tends bar for the Colvilles has been arrested for the crime, Henry soon discovers that the murder rests on complex motives reaching far beyond the Caribbean.