Magical Girl Lyrical Nanoha: Reflection

Mahou shoujo ririkaru Nanoha: Reflection is a movie starring Satomi Sato, Yukari Tamura, and Haruka Tomatsu. While Nanoha attends 5th grade, a planet is slowly dying.
The planet Eltria, having suffered severe desertification in the past, has all but been abandoned. Against her older sister's wishes, Kyrie Florian travels to Earth alongside her best friend, the AI Iris, in search of the key to their planet's regeneration. However, the only way to find it lies within the Tome of the Night Sky, leading them into conflict with Nanoha and her friends.