Dick Francis: Hot Money [1996] hardback

Multi-millionaire Malcolm Pembroke's colourful life has included five wives and nine children. When his fifth wife is murdered, he patches up a quarrel that has been simmering for nearly three years with his favourite son Ian, and asks for help. Ian Pembroke, who detested the fifth wife Moria, agrees to meet his father at Newmarket yearling sales. From here he is instantly whirled into a horrifying race against time to find Moira's murderer before the maniac can strike again. Greed, malice and lethal ploys lie ahead on the rocketing journeyings of father and son as they track the killer remorselessly. Yet they are still able to grab some enjoyment along with the peril as they find time to watch many of the world's top races.