Kyrie Florian's home planet Eltria is dying and her father Granz has fallen ill with it. Against her older sister Amitie's wishes she leaves with her friend Iris for Earth, after the Eternal Crystal that Iris says can heal both the planet and Granz. Getting to it runs her into Nanoha Takamachi, Fate Testarossa and Hayate Yagami, who hold the other half of what she needs. This third Nanoha film opens a two-part story that Detonation finishes, and it draws on the games rather than on the television seasons.