Joyce Cave had her husband, Robert, exactly where she wanted him - in a private gaol with herself, her aunt and her uncle as warders. He had been charged with killing the local good-time girl, who had tried the oldest trick in the world on the panicky Robert and ended up in the canal for her pains.

But Joyce hadn't bargained on John Trewen Forbes, a slick operator with schemes to rid himself of his young cousin Lucy, who was following the dangrous course of not parting with any of the proceeds of her inheritance.