Even Money by Dick Francis,Felix Francis

On Royal Ascot's first day, bookmaker Ned Talbot watches helplessly as a string of favourites come in. With the punters totting up their winnings, he counts his losses.
Then an old man steps forward with a very different claim. The father Ned never knew - believed to have been killed in a car crash long ago - is standing before him.
Barely an hour later, Ned's newly-found father is dying in Ascot's car park. Stabbed by an unknown assailant, he warns Ned: 'be very careful'.
But of whom? Of what?
Ned races to discover the truth behind his father's disappearance and sudden reappearance. It's not just money on the line now. It's lives . . .
Packed with intrigue and hair-raising suspense, Even Money is just one of the many blockbuster thrillers from legendary crime writer Dick Francis.