Vasya was orphaned, in the village they called her a witch. And she can either go to a monastery, or let her older sister arrange her marriage with the prince. Both options lead to life in a tower, cut off from the vast world she wants to see. So she chooses adventure, rides off on horseback into the forests, disguising herself as a young man. When a fight with the bandits tormenting the surrounding area allows her to earn the favor of the Grand Duke of Moscow, she must carefully keep the secret of her gender in order to remain in his good standing, even when she realizes that his kingdom is threatened by mysterious forces that only she can stop.