 Amelia initially calls him "The Master Criminal," although his "nom de guerre" is eventually revealed to be Sethos.Sethos is initially presented as a rival to Emerson for Amelia's affections, but later becomes an important part of the Emerson's large circle of friends, allies, and acquaintances in later books when it is revealed that he is Emerson's theretofore unknown half-brother, Seth.The Emerson family expands again during the 1897-1898 season while on an archaeological expedition to Nubia.