Hordes of people are on their way to Derby Day at Epsom Downs: dukes and dust men, bishops and beggars, privileged ladies and prostitutes. The gamut of Victorian society and a hotbed for crime and crooks of all kinds.

Detective Inspector Robert Colbeck and his assistance a assigned to the case of the disembodied head, a murky course of events that takes in murder, fraud and race-fixing. Just how much is someone prepared to risk in order to win?