Good old Uncle Willie—known for an insatiable sweet tooth and being an epic pain in the rear—has come to stay with the Redpaths for the holidays. As luck would have it, he's found dead in the snow, in a Santa suit on Boxing Day. It seems as though someone may have poisoned his chocolate...or was it the mince pie? As the police flock to the house, Willie's descendants, past lovers and distant relatives are drawn into a perplexing investigation to find out how the old man met his fate, and who stands to gain by such an unseasonable crime.