Mikazuki's group, Tekkadan, is commissioned to escort Kudelia on an inspection of a halfmetal mine. Under Tekkadan's protection, she completes the inspection schedule without incident. But suddenly, Tekkadan finds itself under attack by space pirates.

Deploying all of its fighting strength, Tekkadan attempts to capture Sandoval Reuters, the leader of the Dawn Horizon Corps. Gjallarhorn's outer lunar orbit joint fleet Arianrhod also joins the battle, turning it into a three-way free-for-all.

Gjallarhorn receives a mediation request from the SAU. In order to break the prolonged stalemate, McGillis personally enters the battlefield in a mobile suit. Galan's team launches an attack on McGillis, who is whittling down Arbrau's fighting strength.

The fighting ends as the rival economic blocs SAU and Arbrau agree to peace negotiations. As they remember their fallen comrades, the members of Tekkadan decide to withdraw from Earth.

Via a certain matter on Earth, the connection between Tekkadan and McGillis grows even stronger. Meanwhile, the Gundam Vidar, which has been undergoing adjustment by the Arianrhod fleet, finally rolls out.

Tekkadan has discovered a huge object at a mine it is managing. Having received a message from Orga about the object's true nature, McGillis decides to pay a secret visit to Mars.

The awakened mobile armor, along with a huge quantity of sub-units, heads for a densely populated area to begin its attack. Tekkadan attempts to hold back the onslaught, but is helpless against its overwhelming power and superior numbers.

Outnumbered, Tekkadan turns to McGillis for assistance, and launches a mobile armor mopping-up operation. Meanwhile, a strange phenomenon occurs in the Gundam Frames that are confronting the mobile armor.

Tekkadan has been thwarted in its attempt to rescue Turbines from danger. Orga restrains himself in response to Naze's wishes, but...

A modest funeral service is held aboard the Saisei. But Jasley has been preparing yet another stratagem.

Gjallarhorn's Earth headquarters has been captured in a coup d'état by young officers. Among them is McGillis, who heads for a facility underneath the headquarters.

The Arianrhod fleet, led by Rustal Elion, attempts to gather all its forces to fight the coup d'état.

After many complications, Tekkadan finally joins the battle against the Arianrhod fleet, but...

Tekkadan revives and launches an attack, aiming to escape the battlefield. Meanwhile, the fight between McGillis and Gaelio becomes increasingly ferocious.

Tekkadan is in a difficult predicament. A huge Gjallarhorn force then begins deploying around its Martian headquarters.

Gjallarhorn begins its Tekkadan mopping-up operation. Facing this, Tekkadan's future is...

Tekkadan has finally made it to Earth, successfully introducing Kudelia to Arbrau's representative, Togonosuke Makanai. However, they will have to accompany Makanai to a parliamentary general session taking place in Edmonton.

In the midst of ongoing protests by citizens of the Martian colony Chryse demanding independence from the Earth government, the Chryse Guard Security is assigned to protect Princess Kudelia Aina Bernstein on her diplomatic mission. When the CGS headquarters is suddenly attacked by Gjallarhorn forces, the Third Army Division, having just been abandoned by their superiors, strike back with the ancient Gundam Barbatos, piloted by Mikazuki Augus.

The adults of CGS flee in the face of Gjallarhorn's attack, using Mikazuki and the other children as decoys. Gathering the children who have been left behind, Orga decides to fight back against Gjallarhorn, and puts a certain plan into motion.

Having demonstrated Tekkadan's strength and legitimacy to Naze, the leader of Turbines, Orga and the others renew their negotiations with Teiwaz. Meanwhile Atra visits Turbines's warship, bringing the frustrated Kudelia with her.

Accompanied by Naze, Tekkadan visits the Saisei, the stronghold of Teiwaz, in order to meet with Teiwaz's representative McMurdo Barriston. Here, Orga receives a surprising proposal from Naze.

A conflict between the rival economic blocs Arbrau and SAU breaks out as their armies clash on the Balfour Plain. Tekkadan also joins the battle under the command of Galan Mossa, but its members become exhausted as the war of attrition continues for days.

Thanks to Mikazuki and the Gundam Barbatos, Orga's group has temporarily repulsed Gjallarhorn, though not without many sacrifices. As they are discussing their next move, one of Gjallarhorn's Graze mobile suits again appears at the CGS base.

The members of Tekkadan need a guide in order to reach Earth despite Gjallarhorn's surveillance. To gain a powerful backer, they attempt to negotiate with Teiwaz, which is based in the Jupiter Sphere.

Tekkadan and Turbines go on ahead to Earth, leaving Mikazuki and Yukinojo on the Saisei to complete final adjustments to the Barbatos. But the events aboard the Saisei have greatly affected their respective states of mind.