Richard Jury is in hospital recovering from three bullet wounds from his last case when Melrose Plant overhears a conversation in the bar (The Grave Maurice) across from the hospital about Jury's doctor. It seems the doctor's 15-year-old daughter, Nell, went missing two years earlier along with one of the family's thoroughbred horses.
Jury sends Plant out to the Ryder farm pretending to be interested in horses and investigate. Good mystery.