|“||She was very beautiful... like you, but dark, with nearly black eyes and hair, and a firm, square jaw when she was stubborn. She had a fierce temper and a passionate nature, but she was gentle with her friends. We called her Mercy, though she had none.||”|
|— Alexander Gericault to Amanda|
Mercedes awakened in 1809, after watching her youngest son die. An old man named Senex helped her begin the last rites, and suddenly she saw an angel merged with her, its hands as bloody as her own. Her natural wisdom guided the knives that became her weapon of choice. She was a prodigy even among the Old Man's elite students, and certainly worth the risk he took in coming to Earth for her.
In March 1887, Mercedes, Senex, and Alexander Gericault, a covert nephandus mage, celebrate the assassination of an industrial giant. While dancing, Gericault admits to Mercedes that he has fallen in love with her.
In May 1889, while vacationing undercover as British gentry Mr. and Mrs. Melvin Abercrombie, Gericault reveals to Mercedes that he is a Nephandus. He was supposed to spy on Mercedes and Senex, discover their weaknesses, and direct them to their common enemy, the Physician and the Technocratic Union. He only remained because he fell in love with Mercedes. He says he has to leave, and asks her to join him.
In October 1896, Mercedes steps into a Caul, prepared to become a Nephandi barabbi. She does this out of love of Alexander Gericault. In December 1923, Mercedes and Alexander face off against Senex. Senex shows Mercedes how twisted her Avatar has become. She willingly hesitates the split-second he needs to kill her.