Banned from the Valley of the Kings, Amelia Peabody and her distinguished husband have returned to England with their 19-year-old son Ramses and their foster daughter, Nefret. Ramses is secretly in love with Nefret and plans to flee to Germany to avoid temptation. Then a mysterious visitor changes the plan for the whole family. Prince Tarek from the Lost Oasis has written to the Emersons, asking for help. His only surviving son is ill with a mysterious malady and his throne is under threat.