Mobile Suit Gundam SEED - Season 2 Episode 18 Attack the Lohengrin!
Overview: The Minerva must destroy a fixed positron cannon emplacement to break through to Gibraltar. Though hesitant at first after meeting Shinn, they are helped by a young resistance fighter named Coniel, who provides data of a secret tunnel that will lead near the positron cannon. The Minerva and the other ZAFT forces draw out the Earth Alliance mobile suits and mobile armor while Shinn heads through the tunnel and destroys the cannon.