After colliding with the Gate of Zedan, the asteroid Axis is now falling toward the lunar city of Granada. The Argama travels to Axis, hoping to use the asteroid's communications facilities to contact the AEUG fleet so that they can deflect it with the captured colony laser. Their efforts are interrupted when Rosamia attacks in a formidable new Psyco Gundam, and Kamille makes one last attempt to reach out to the woman he once knew as Rosammy.

The AEUG launch Operation Maelstrom, surrounding Gryps 2 in a whirlpool formation in order to recapture the colony laser from the Axis forces. Kamille is sent to distract the enemy and finds himself in single combat with Haman herself. The two powerful Newtypes experience a mental connection, but Haman rejects this rapport and lashes out against Kamille with violent anger, crushing his hopes that they might come to understand one another.

Scirocco and Jamitov visit the Axis flagship for a final round of negotiations with Haman. The AEUG learn of the meeting, and hotheaded Katz Kobayashi decides to sneak aboard the ship and get rid of Scirocco and Haman. As the situation descends into chaos, the treacherous Scirocco takes his opportunity to seize control of the Titans. Haman confronts Scirocco as he makes his escape, and Katz intervenes in their duel with tragic results.

Desperate to save Granada from the colony laser, the AEUG's sponsors send the Argama to negotiate an alliance with the Axis forces. Axis leader Haman Karn accepts the AEUG proposal and agrees to betray the Titans. As the Argama and Radish launch a diversionary attack on the Titan fleet that surrounds Gryps 2, the Axis flagship moves into position to attack the colony laser. But can they trust Haman to keep her word?

The Titans are moving their Gryps 2 colony laser into position to fire on the lunar city of Granada. In order to divert the AEUG from this threat, Bask begins another attack on Side 2. Rosamia, who has now returned to the Titans, joins the battle in a powerful new mobile armor. Kamille tries to reason with her, only to find that she is no longer the Rosammy he once knew.

Titan commander Bask Om launches a poison gas attack against the space colonies of Side 2, assigning Reccoa Londe to command the operation as a test of her loyalty. The Argama rushes to the rescue, but its mobile suits arrive too late to save the target colony. And when Rosammy enters the fray to help Kamille, the stress of battle and the shock of seeing the attack's victims cause her to reawaken as the Cyber-Newtype Rosamia Badam.

Rosammy joins Kamille aboard the Argama, but the other AEUG members are suspicious of this strange young woman, and suspect she may be one of the Titans' Cyber-Newtypes. Meanwhile, the AEUG learn that the Titans have converted the space colony Gryps 2 into a giant laser cannon. Kamille is dispatched on a reconnaissance mission to confirm these reports, only to find himself confronting a dear friend who has now joined forces with the enemy.

After Kamille fails to rescue his mother from the Titans, the AEUG are forced to hand him and the captured Gundams over to the enemy. But Emma, horrified by the actions of her commanders, decides to defect to the AEUG. With Kamille, his father, and all three Gundams in tow, she makes a desperate attempt to escape to the Argama.

The Argama docks at Side 2's Colony 13, a neutral sightseeing colony, for another round of repairs. Kamille and Fa enter the colony to enjoy some leisure time, only to encounter a young woman named Rosammy who insists that Kamille is her long-lost brother, as well as a vacationing Mineva Zabi. Char discovers that the Titans have stationed snipers inside the colony's agricultural modules, and the ensuing fighting soon spills over into the colony itself.

Char and Kamille launch into orbit aboard a space shuttle to rejoin the Argama. They arrive to find the Argama under attack by the Alexandria and its mobile suits. Char targets the enemy ship with his mega bazooka launcher, but the Alexandria withdraws from the firing line just in time. Kamille senses a familiar presence aboard the Alexandria, but he can't bring himself to believe that Reccoa is still alive.

Char and Kamille travel with their Karaba allies to the Earth Federation capital at Dakar. Here they take control of the Federation assembly so that Char can deliver a speech denouncing the evils of the Titans. Jerid and his comrades attempt to destroy Dakar's communications center in order to stop the broadcast, but their actions serve to turn both the politicians and the public against the Titans.

Returning alone to the Kilimanjaro base, Kamille is finally reunited with Four Murasame. But Kamille's old enemy Jerid Messa is also at the base, and when he recognizes Kamille the pair are forced to flee for their lives. The Karaba forces resume their attack, and Four undergoes a dramatic personality shift, turning before Kamille's eyes into an emotionless fighting machine. As Kamille struggles to reason with her, Jerid intervenes with tragic results.

The AEUG's Karaba allies are staging an assault on a Titan base at Mount Kilimanjaro. The Argama descends into satellite orbit to support the operation, and Char and Kamille accidentally fall into Earth's atmosphere and find themselves in the middle of the battle. Kamille is astonished to see the Psyco Gundam enter the fray, and when he and Char infiltrate the Kilimanjaro base, they discover that its pilot Four Murasame is very much alive.

Despite the Argama's desperate need for repairs, the AEUG ships are ordered to continue their pursuit of the Gwadan and Dogosse Gier. Meanwhile, Reccoa is recovering from the injury she sustained while protecting Char, but she is frustrated by his callous attitude. When Yazan Gable launches an attack on the AEUG ships, Reccoa ignores Char's warnings and joins the battle, convinced that somebody is calling to her from the darkness of space.

Bright, Char, and Kamille join an AEUG delegation to the Axis warship Gwadan. Here they meet Mineva Lao Zabi, the child leader of the Axis forces. Char is outraged to discover that Mineva is being used as a puppet by her regent Haman Karn, and the negotiations quickly collapse. As the AEUG members make their escape from the Gwadan, Paptimus Scirocco sees an opportunity to establish his own alliance with Axis.

Forced to leave Von Braun City before completing its repairs, the Argama sets off on its diplomatic mission, only to find that the Titan flagship Dogosse Gier is also on its way to meet the Axis forces. With the AEUG's sponsors determined to contact Axis first, Char and Reccoa attempt a daring preemptive strike on the enemy ship. As the fighting intensifies, a new power enters the battlefield.

The asteroid Axis and its army of Zeon renegades are returning to the Earth Sphere, and the AEUG hopes to enlist their help in the struggle against the Titans. Before contacting the Axis forces, the Argama docks at the lunar city of Von Braun for repair and resupply. But when Kamille runs into Sarah Zabiarov in Von Braun City, he learns that the Argama is in deadly danger from the bomb she has planted at the city's spaceport.

In an attempt to destroy the Argama, the Alexandria uses Yazan's forces to drive the AEUG warship into a ruined space colony, where Jerid and Mouar are waiting in ambush. Kamille rushes back to protect the Argama and begins a fierce duel with Jerid. But Mouar, who has sworn to protect her partner, won't let him fall before the power of the Zeta Gundam.

Char and Kamille return to the AEUG flagship Argama with the captured Gundams. Meanwhile, the Titans dispatch the warship Alexandria, as well as reinforcements from the regular Federation Forces, to pursue the rebels. Titan pilot Emma Sheen is sent to the Argama to deliver a message from her commander Bask Om, but she is as shocked as the AEUG when the nature of Bask's ultimatum is revealed.

The Titans launch a new offensive against the space colonies of Side 2, where the AEUG enjoys strong support. Side 2's civilian leaders attempt to surrender, but the Titans are intent on carrying out a poison gas attack to teach the rebellious colonies a lesson, and the Argama and its mobile suits are the only ones who can save millions of innocent people from being massacred at the Titans' hands.