Theresa "Tessa" Gray is an American warlock, a special kind of warlock—the only half-Shadowhunter, half-Eidolon demon. She moved to London in 1878 and her life has since been entangled in the lives of the Nephilim. Theresa Gray was born to an unmarked Shadowhunter named Elizabeth Gray and the Greater Demon, Belial, disguised as the mundane Richard Gray—Elizabeth's husband and the man who would raise her as his own, and whom everyone believed was her father. Under normal circumstances…