Professor Gregory Parton's team digs up manacles and mutilated corpses with the wreck of the aristocratic Carr family's 18th century ship Somerset near a Bristol channel bridge. It seems a beached 'tringular trade' slaver, which stirs modern political commotion, just now Afro-American presidential candidate senator Joy is visiting England. But DNA proves the bodies aren't slaves, Admiralty records the ship was falsely reported destroyed in Northern America. More research unearths a long-covered story involving Oban's Jamaican Maroons and George Washington. It's political dynamite, and violence follows.