Sethos (Peabody mysteries)

Sethos is the nom de guerre of the shadowy "Master Criminal" in the Amelia Peabody series of historical mystery novels.

He is first encountered in The Mummy Case, as the mastermind of an organized gang of thieves attempting to steal antiquities from Dahshoor, in which he is partially foiled by Amelia Peabody and her husband, Radcliffe Emerson. To their surprise, he reveals that he has spent most of the novel right under their noses, pretending to be a Coptic priest of the local village. Despite his disguise, Amelia feels sure he is English in origin.

In Lion in the Valley, his nom de guerre is revealed, and he is thus described by an Englishman who hears of him during his brief foray into slum life:

Amelia becomes obsessed with the idea of apprehending the Master Criminal and putting a stop to his activities. By the end of Lion in the Valley she is captured by Sethos, but astonished when he professes to be passionately in love with her. Amelia is starting to believe that she may be able to reform him when Emerson bursts in and fights with Sethos, who manages to escape. After realizing that he cannot have her, he promises never to harm or threaten her or her family.

He reappears in the novels from time to time, often to rescue Amelia from other foes. Despite her occasional entreaties, he never gives up his illegal activities, which he takes considerable pride in.

He is presumed dead at the end of The Snake, the Crocodile, and the Dog and again at the end of He Shall Thunder in the Sky, at which point it is revealed that he has been working for British Intelligence during the Great War.

It is revealed in He Shall Thunder in the Sky that "Sethos" is actually Emerson and Walter's half-brother, the illegitimate son of their father and his mistress, who had been their mother's best friend. He spent his childhood hating Emerson for having the recognition and childhood he craved, not knowing that Emerson spent his own childhood loathing his situation and searching for a way to remove Walter and himself from their mother's grasp.

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