When millionaire banker, Preston Still, kills his wife's lover by pushing him down the stairs, he looks to the family au-pair to help him dispose of the body.

But the au pair belongs to the Saint Zita Society, a self-formed group of drivers, nannies and gardeners, who are servants to the rich - and whose intentions are not entirely benign.

Accident murder, illicit affairs, and a young man recently released from a hospital for the criminally insane come together with devastating consequences in Ruth Rendell's gripping new crime novel.