Yielding to pressure from the Earth Alliance, the government of Orb has agreed to join the fight against ZAFT. An Orb expeditionary fleet commanded by Yuna Roma Seiran is dispatched to back up Neo Lorrnoke's Phantom Pain.

Meanwhile, the tensions among the Minerva's pilots have begun to ease thanks to the influence of the cheerful newcomer Heine. Though Athrun is troubled by the prospect of fighting against Orb, he now has a better understanding of Shinn's feelings toward his homeland. The Minerva leaves the Black Sea to intercept the approaching Orb fleet, and the two sides meet in battle in the Dardanelles.