For Kicks by Dick Francis. Pocket Books 1965
Good quick read.
In this, one of Francis' earlier books, Daniel Roke, and Australian, is hired by the Earl of October to try and discover how someone is fixing races by drugging the winners with an untraceable drug.. To do this he masquerades as a stable boy and shifts from horse yard to horse yard until he discovers who is doing it and finally how it is being done. In doing so, Daniel places himself and Elinor, the young daughter of the Earl of October, at considerable risk. In a final confrontation with the bad guys Daniel overcomes his adversaries but is thrown in jail accused of murder to await the return of the Earl of October.
Like most of Francis' protagonists, Daniel is youngish, handsome, honest beyond measure and quite capable at a number of things useful to someone working with horses. A sub plot to the main story is the wrongful accusation of Daniel by the older Earl's daughter of sexual abuse and his growing involvement with the younger.
To the seasoned Francis reader, this book does not have too much depth but like all Francis mysteries, a joy to read.