Gundam Wing Episode 18

Une uses a threat to get the scientists to agree on building a mobile suits that will be as good (or better) than the gundams. Meanwhile back on Earth, Zechs has turned himself in to OZ and has a conversation with Treize, who asks if Zechs will still fight for Romefeller against the gundams. Zechs says he cannot and Treize tells him he will executed by OZ staging a battle between him and 60 mobile suits. Treize tells Zechs that he will die in glory. Actually, Treize has arranged the battle so that Zechs has a few people to help him get Tallgeese repaired and ready to fight, in order to make his escape more certain.

Quatre's shuttle, which he is barely piloting thanks to approaching unconsciousness, is intercepted first by a squadron of remaining Federation troops and then by OZ troops. The OZzies attack the Feds and before he dies, a Federation officer allows the now unconscious Quatre to get away in a space-type Leo. Back on the Moon Base, the scientists learn of the mobile doll program and strenuously object to it.

At a test of the mobile dolls, Treize surprises Dermail and Tsubarov by getting into a Leo and attacking the control booth. He gives the soldiers around the two Romefeller leaders order to kill Tsubarov. They almost do, before Treize calls it off and tells the Chief Engineer that he needs to respect the human aspect in war. When the time of Zechs' execution comes, he blasts his way off of the ship he was supposed to sink in. There are a huge number of both Aries and Cancer suits after him and he manages to take out most of them. At one point Tallgeese plummets into the water and Zechs has to face off with the Cancers. As he fights, his mask breaks apart, signalling the end of his association with Treize and OZ.

Heero, back on a colony and enrolled in a new school under the name Duo Maxwell, gives a long speech about why people are in space and what war means. As he finishes, we see Tallgeese lying on a beach and an unconscious Zechs underneath it.