Private investigator Sid Halley has a new left hand, having had a transplant since his last appearance in 2013's Refusal. After receiving death threats, an ex-jockey trainer friend calls to ask for his help, but Sid is preoccupied with recovering from surgery and saving his crumbling marriage. When his friend is found dead, Sid blames himself. Sid starts to investigate and soon finds himself embroiled in a conspiracy that cuts to the very heart of the integrity of British horse racing.