Forfeit
by Dick Francis (1968)

When reporter Bert Checkov falls to his death, his colleague James Tyrone thinks he can prove it was murder. But there’s no such thing as a sure thin.

This early story has an unusual amount of sex for a thriller. It takes some time to establish the characters and ramp up the tension. It’s not until the third act that the action takes place and we get what is expected from a Dick Francis book.