A hybrid of investigative journalism, historical analysis, and personal reflection that examines humanity’s evolving relationship with evil through the figure of the Devil. Sullivan explores the Devil's origins from ancient mythologies to Christian theology, referencing thinkers like Zoroaster, Augustine, and Baudelaire, while also recounting his experiences attending a Black Mass in Mexico and investigating a 1988 death in Texas linked to Satanic panic. The book delves into theological debates, cultural rituals, and modern events to explore how belief in the Devil has faded in the West, yet Sullivan argues that evil persists in forms we often rationalize or deny. Reception has been mixed: some praise its ambition and storytelling, while others criticize its Christian-centric lens and structural inconsistencies. (Medium Discount)