Traveling to Europe under strange circumstances, attorney Stone Barrington finds himself at the center of an unusually complex mystery involving two unexpected invitations and an intricate puzzle that leads him into the rarified world of European billionaires.

Belgian detective, Hercule Poirot, whose simple Christmas "repast" is disturbed by an invitation to visit the home of Simeon Lee, a repellent curmudgeon who makes Mr. Potter look like George Bailey. "My life is in danger," he states. Events snowball as Simeon is indeed killed, and a fortune in uncut diamonds stolen.