Magical Girl Lyrical Nanoha the Movie 2nd A's

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 Nanoha Takamachi and her friends. The reunion between the two new-found friends are cut short however, when they are assaulted by four ancient magic users who identified 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".