The Prince's Spy is based on a 3000-year-old story from Egypt, known as The Tale of the Treasure Thief, an ancient locked room mystery. The investigator, Sunero, originally a land agent in the employ of the King's Son Khaemwase, has become the Prince's most trusted servant and is now known as the Prince's Eyes and Ears or, more simply, the Prince's Spy. He was sent to the city of Waset to investigate an audacious robbery perpetrated by three generations of the same family, involving systematic theft from the royal storehouse known as the Treasury, at the King's Mansion Temple. Since the prime suspects were highly respectable, pillars of Egyptian society, Sunero had to play a waiting game, getting close to the family, keeping them under surveillance, hoping that one of them would make a mistake. By the time Sunero and his master know the 'who?' of the crime the 'how?' is still a mystery. Khaemwase has been waiting for the revelation of that secret so that he can die with his intellectual curiosity satisfied. This detective story is told in flashback as the eponymous Spy and his friend, the Count, try to keep their master's interest in life.