Mary Heaton is a respectable middle-aged widow, with a daughter who recently went off to university and a husband who until his death was a senior member of the cabinet. Her friends regard her as a little stiff and a little old-fashioned, but mostly as a very straight-laced woman. And then, one morning, a letter arrives with a threat to reveal the truth about Mary's past. Thirty years ago, Mary and her husband Donald made a fortune as producers and...