Six months have passed since the events of the previous movie . Fate Testarossa has returned to Uminari City with Lindy Harlaown as her legal guardian and is living the life of a normal elementary schoolgirl along with Takamachi Nanoha and her friends. The reunion between the two new-found friends is cut short however, when they are assaulted by four ancient magic users who identify themselves as the Wolkenritter . As the motives behind the actions of the Wolkenritter become clear, Nanoha and Fate find themselves in a race against time to stop the reactivation of a highly dangerous artifact known as The Book of Darkness .
