Charlotte Pitt's grandmother Mariah Ellison finds herself investigating a long-unsolved slaying, and it becomes clear that grappling with intrigue and foul play runs in the family. A festive Christmas package left on Mariah's doorstep contains an ominous present, sparking memories of a twenty-year-old murder that shattered her friendship with the victim's widow. Mariah travels to Surrey and joins forces with the murdered man's grandson, a sleuth in his own right who's discovered promising evidence as well as a suspect.