Simeon Lee has demanded that all four of his sons—one faithful, one prodigal, one impecunious, one sensitive—and their wives visit the family home for Christmas. But the cantankerous patriarch has anything but a heartwarming family holiday in mind. He bedevils each of his sons with barbed insults, while at the same time lavishing attention on his very attractive, long-lost granddaughter. Finally he announces that he is cutting off his sons' allowances and changing his will to boot.
So when the old man is found lying a pool of blood on Christmas Eve, there is no lack of suspects. Did Lee's taunts push one of the boys or their wives to a desperate act of murder? Or was the killer really after the fortune in uncut diamonds Lee kept locked away in his safe? And how did the murderer escape from the locked room?
Intrepid Belgian detective Hercule Poirot suspends his holiday sorting through the myriad suspects and motives to find the truth behind the old man's death.