Endless Poem is the twenty-fourth episode of Mobile Suit Gundam 00
Two years ago, Sumeragi introduced Setsuna to the other Meisters as the pilot of the Gundam Exia. Allelujah was concerned because Setsuna was a child, but Sumeragi said his test scores met their standard. Tieria asked if he was chosen by Veda, and Sumeragi said he was. Lockon said age was irrelevant because they all made resolutions to change the world with Gundams.
In the present, Setsuna cries out in grief over Lockon's death. Hong Long tells Wang that they've received a message about the ship battling the GN-X squad, and Wang wonders if the world will lean toward the UN or Celestial Being. Tieria grabs Setsuna and angrily tells them that their forces were divided because Setsuna went to Earth. He asks why Lockon had to die, and Sumeragi slaps him. She tells him the enemy is out there, so if he has time to cry, he has time to work. Feldt cries while holding Haro in her arms, and it apologizes, but she tells it there's nothing to apologize for.
On the last Virginia transport, Sergei examines the results of the last battle: out of 27 units, only 11 returned, and they don't know what happened to the Throne Zwei. Combined with the new Trans-Arm ability, Sergei tells Kati that they'll just lose men in vain if they keep fighting. Kati agrees, but she says they have orders to attack again because reinforcements are on the way. Patrick's GN-X returns to the ship, and Kati tells him she was worried. Soma wonders if Allelujah found a way to block her brainwaves, and she vows that as a perfect super soldier she won't lose to a defective test subject.
Ian sends out several satellites emitting GN particles to distract the enemy. Sumeragi asks him about the mobile suit status, and he reports that the Gundam Kyrios can launch without the tail booster, and they removed the Virtue armor on the Gundam Nadleeh. Tieria calls Sumeragi to ask for the next mission plan, and she asks him if he intends to fight. He says they can show their strength to the world if they defeat the GN-Xs. Sumeragi says the risk is too great, and Tieria tells her it's the resolve of all the Meisters. Setsuna hooks up Haro to a video monitor to watch Lockon's last battle and sees that it was Ali who killed Lockon. Setsuna wonders if Lockon threw away his life for vengeance, and he recalls his comrades from his guerilla days. He also recalls what Lasse said and realizes that the point of existing is to use one's own will to carry on the will of the dead and face the world.
The Virginia picks up the GN particle asteroids, and Sergei immediately recognizes them as decoys. Suddenly, the gold mobile armor Alvatore arrives, piloted by Alejandro. On the Ptolemaios bridge, the crew takes a moment to relax. Feldt writes a letter for her parents and Lockon because she won't see them for awhile. Christina thinks about writing a letter to the adopted mother she left behind. Christina asks Lichtendahl about his family, and he says his parents were space elevator engineers who were killed during the solar wars. Lasse notes that this is the first time they've talked like this, and Christina says it's because they had to keep everything classified. Allelujah worries about the Gundam Nadleeh not having the Trial system, and Tieria says he'll fight to avenge Lockon. Feldt puts the letter in the Gundam Dynames' cockpit and asks Setsuna if he has anyone to write a letter to, but he says no, which she thinks is lonely. Setsuna says that Lockon is the lonely one and tells Haro to stay with him. Suddenly, the GN-X squad is detected, along with the Alvatore. Alejandro fires a beam cannon and hits the Ptolemaios' port side.
A second shot comes in and grazes the starboard side. Lasse launches in the assault container, while Lichtendahl moves the ship behind a nearby asteroid. Sumeragi orders Tieria and Allelujah to launch from the container and defend the ship. Sergei leads the GN-X squad and orders everyone to flank the Ptolemaios. Patrick and several other GN-X pilots approach the ship, but Tieria attacks them with his beam rifle. Hallelujah uses his shield pincer to destroy a GN-X and attacks Soma. Sergei steps in to help, forcing Hallelujah to fall back a bit. Lasse opens fire on Alejandro with missiles and beam cannons, but the Alvatore blocks them with a GN field. Alejandro fires the beam cannon again, which damages both the Gundam Kyrios and the Ptolemaios. Christina reports that the medical room was destroyed, and Dr. Moreno's body floats through the wrecked infirmary. With the most recent damage, the ship is unable to raise its own GN field, and Sumeragi decides to go to the assault container to shoot down the Alvatore.
Tieria activates Trans-Am mode and destroys several GN-Xs, but he's hit by another attack from Alejandro and loses a leg. Patrick and another pilot bombard Tieria with beam fire and blow off an arm and both legs. Patrick and Tieria fire at the same time, which results in the GN-X losing its upper body and the Gundam Nadleeh losing its head. Although the Gundam Kyrios is missing an arm and a leg, Hallelujah continues to fight with Sergei and Soma.
Sumeragi and Ian attack Alejandro, and Christina lies to Feldt about a problem with the Gundam Dynames' reactor to get her to leave the bridge. A GN-X closes in and is hit by GN missiles, but it continues its attack and blasts the bridge. Just before the explosion, Lichtendahl jumps out of his seat to shield Christina. Ian opens fire and destroys the GN-X. Lichtendahl and Christina float in space, and Christina is shocked to see that Lichtendahl has cyborg parts. He says that he was attacked alongside his parents, so his body is half cyborg as a result. Christina cries and says she was a fool because a good man was next to her all along. Lichtendahl then dies, and Christina presses him close to her. Sumeragi calls Christina on the radio, and Christina tells Feldt to dress up more and live for Lockon to change the world. Christina then dies from the metal shard impaled through her body, and the bridge explodes.
Lasse and Setsuna continue to fire on the Alvatore to no effect. Lasse rams the assault container into the Alvatore, but the Alvatore's GN field repels them. The Alvatore's arms then grapple onto the assault container. Alejandro says that he'll make the accursed ghosts of Aeolia sacrifices for the new world. As the assault container begins to crumple, Lasse ejects in the GN Arms, followed by Setsuna. The Gundam Exia then rushes forward at the Alvatore.