A young woman named Vanessa Ives becomes entangled with a mysterious explorer and his American gunslinger companion as they investigate the dark supernatural underbelly of Victorian London. Together they encounter iconic literary monsters and occult horrors drawn from Gothic fiction, including vampires, werewolves, and demonic forces. Vanessa herself is haunted by a terrifying evil that has marked her as a target, making her both a weapon and a potential vessel for darkness.