The Castle, an exclusive group of houses built around a gold course, is a safe haven in a nation troubled by the war in Vietnam, political assassinations, and the growing shadow of Watergate. For the disillusioned publisher Hamer, it is an escape from a world that has disappointed him. For Hamer's wife, Kathryn, it's become a close community and support network.

But something is very wrong in the Castle. A teenage boy has gone missing. There are thefts, threats, shootings. Hamer and Kathryn have begun to fear that the Castle may not be so safe after all, that they and their neighbours are the targets of a conspiracy with a single purpose: to destroy five families and punish them for the sins of their children. And one of those families could be his own.

A siege has begun. And blood will out.

An exceptional and unforgettable historical thriller, The Castle is about secrets: the secrets of the state, the secrets of families, and perhaps the secrets we hide even from ourselves.