Invited by the oldest customer of his rural Lincolnshire pub to a local Horse Trial event, Ex-Met Inspector John Cannon suspects there is an ulterior motive. There is, the first of many with more deadly outcomes as Cannon finds himself plunged into the ruthless ambitions of some in this horse-focussed world. The inheritance of a family fortune is also an issue. The stakes just get bigger all the time. Local tragedies, murder and kidnap take the action to America. Now Cannon begins to realise the scale of gangland crime involved, and just how many lives have been blighted.
In Kentucky it is made worse by two rival gang leaders both believing they have a horse that will win the Kentucky Derby. The climax comes on the track as this world famous race is taking place, but not before Cannon has experienced the wilder, lonelier, beautiful stretches of Louisiana as he tries to rescue the maltreated kidnap victim.