A woman is found murdered in her bed with thirty coins in her mouth, and Dwayne's police shield under the bed initially makes him a suspect. On investigation, the woman is found to have been living under a false name and under protection as an informant of London's Serious Organised Crime Agency, who have a man on the island. Poole believes the killer is still on the island looking for incriminating documents the woman had. Events and people conspire to prevent Poole returning to his old job in London.