London, November 1960: The Cold War is at its height.
Spy fever fills the newspapers, and the political class knows how and where to bury their secrets.
When a highly sensitive file disappears, Simon Callington is accused of passing information to the Soviets, and arrested.
His wife, Lily, suspects that his imprisonment is part of a cover-up, and that men more powerful than Simon will do anything to prevent his own fall.
He knows that she too is in danger and must fight to protect her children.
But what he doesn't realize is that Simon has hidden vital truths about his past, and may be found guilty of another crime that carries an even greater penalty.