One fateful evening in 17th-century Bavaria, a mysterious woman arrives in Reimersberg, the town at the end of the Adventurer's Road. The town lies deep in the mountains and the wolf-inhabited forests of a place known as the Valley of Witches. Seldom reached by outsiders, its people are not welcoming; proud of their traditions, they frown upon change and those who bring it.
Ilsa saves the life of a sick boy, Karl, but is suspicious of the cause of his sickness. And while she earns the boy's undying love, she also attracts the enmity of the town elders - in particular the incompetent doctor and the mayor, Meister. Ilsa's presence in the town awakens a long-hidden darkness, and she finds herself, together with Karl, fighting to survive on a path far more strange and perilous than she could ever have imagined.