After the great success of his latest expedition, the brilliant archaeologist John Bellingham returns from the sandy tombs of Egypt with enough ancient treasures to fill a wing at the British Museum. He visits a friend for dinner and is told to wait in the study. When the friend arrives, he finds the study empty -- Bellingham has vanished into thin air. When Bellingham does not reappear, the police assume he has met with some fatal accident. Because his will cannot be discharged until the time and place of his death are known, Bellingham's family calls on the eminent Dr. Thorndyke, whose mastery of the medical arts is second only to his brilliance for crime solving. As he searches for the true reason for Bellingham's disappearance, Thorndyke discovers a mystery as deep as any pharaoh's tomb.