Italy, 1453. Seventeen-year-old Luca Vero is brilliant, gorgeous—and accused of heresy. Cast out of his religious order for using the new science to question old superstitious beliefs, Luca is recruited into a secret sect: The Order of the Dragon, commissioned by Pope Nicholas V to investigate evil and danger in its many forms, and strange occurrences across Europe, in this year—the end of days. Isolde is a seventeen-year-old girl shut up in a nunnery so she can’t inherit any of her father’s estate. As the nuns walk in their sleep and see strange visions, Isolde is accused of witchcraft—and Luca is sent to investigate her, but finds himself plotting her escape. Despite their vows, despite themselves, love grows between Luca and Isolde as they travel across Europe with their faithful companions, Freize and Ishraq. The four young people encounter werewolves, alchemists, witches, and death-dancers as they head toward a real-life historical figure who holds the boundaries of Christendom and the secrets of the Order of the Dragon.