Heero fights Quatre in a near vain attempt to demonstrate that the colonies no longer need the might of the Gundams, but when that fails, Trowa forces Quatre to realize his own kindness by paying the ultimate price. Meanwhile, the Romefeller Foundation proposes to replace all mobile suits of OZ with their new Virgo mobile dolls and Treize is imprisoned when he refuses to support this. Lady Une, who learns of Tsuborov’s treachery, is shot by Tsuborov when she unlocks Duo and Wufei’s cell, allowing them to escape with their new, yet incomplete suits; Gundam Death scythe Hell and Altron Gundam.

Quatre, now mentally unstable, appears in the newly constructed Wing Gundam Zero and begins to destroy various colonies one by one. Lady Une sends Heero and Trowa to fight back in the Mercurius and Vayeate, while Tsuborov, finding Une’s behavior to be too lenient, stages a coup against her and cuts off the air supply to Wufei, Duo, and the Gundam engineers’ cells.

Part 2:

Duo and an OZ officer, Hilde Schbeiker, clash in ideals as to what will bring about peace, and she comes to his way of thinking. Duo, after running into the five engineers, allows them to turn him in if he gives them time to finish the construction of both his and Wufei’s upgraded Gundams. Meanwhile, Sally manages to locate Wing Gundam, which Heero had left behind on Earth.

Zechs, now going as Milliardo Peacecraft, meets with Lady Une as an ambassador of the Sanc Kingdom. When Nichol begins acting on his own, Une realizes that she’s developed a split personality while trying to execute Treize’s dream of the future and imprisons Nichol upon her return to Barge. Meanwhile, Wufei is captured by Chief Engineer Tsuborov of the Romefeller Foundation.

Heero and Trowa confront Zechs for the first time since their battle in Antarctica and Zechs surrenders willingly. Quatre decides to build the original Gundam that the other five were based on after discovering files in the Winner family computer detailing its designs. Unwilling to compromise to OZ’s ideals, Quatre’s pacifist father evacuates their colony and sacrifices himself to destroy it before OZ can take advantage of it.