But the Wicked Shall Perish follows Tziporah Curiel, a young Jewish woman, as she is brought back to life in 1920s Venice, Italy, and as she struggles to come to terms with her existence and to enact justice on her murderer. The novel incorporates Jewish mythology and beliefs into the first-person narrative through Tziporah Curiel's perspective as she searches for the reason why she died and to bring the person responsible to justice. However, to continue her reborn life, she must absorb living souls, or she will cease to exist. Her decision to strive for justice leads her to accepting a perilous offer from the demon Azazel. With his help, Tziporah follows a path through the fraught political and societal landscape of 1920s Italy and Austria that leads to her discovering the meaning behind her death and justice for her murderer.