Dick Francis - Risk (Penguin Books)

As an amateur jockey, Roland Britten was lucky, and as an accountant he was rigorous. He knew he was on the hate list of several fraudsters, but never thought pen-pushers got kidnapped. And not from a racecourse right after beating the odds to win the Cheltenham Gold Cup. Held prisoner, Britten has no idea who his kidnappers are nor why they have abducted him. Only when resourceful school headmistress Hilary Pinlock gives him the opportunity to escape is he able to seriously think about what has happened and turn his logical mind to track down his abductors...