Finished "Hot Money", by Dick Francis. Malcolm Pembroke is a multi-millionaire gold dealer who has been married 5 times, with 9 children from his various marriages. When his 5th wife is murdered, and this is followed by several attempts of Malcolm's own life, his son Ian, an amateur jockey (there had to be a racing connection somewhere in this
) sets out to try to find who in the family is the murderer.
Absolutely excellent. Perhaps the best in the series yet, although it has many rivals for top spot!