Barnaby looks forward, with reservations, to entertaining his in-laws for Christmas. Meanwhile, exactly 9 years after the suicide of Ferdy Villiers his family and their guests arrive at the somewhat dilapidated Villiers home to celebrate the festive season. However, not everyone present is imbued with the Xmas spirit and the already rather tense atmosphere begins to disintegrate even further when it becomes apparent that someone in the household is all too aware that certain family members have dark secrets to hide. When what initially appears to have been an accident is revealed to be murder Barnaby and Scott discover that they must first unravel what really happened in the past in order to resolve the present.