Mikazuki's group, Tekkadan, has been 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.

Despite some casualties, Tekkadan has successfully repulsed the space pirates of the Dawn Horizon Corps. It appears, however, that this enemy was just one part of a huge space pirate group, and Orga decides to counterattack in anticipation of further assaults.

Deploying all the fighting strength it possibly can, Tekkadan attempts to capture Sandoval Reuters, the leader of the Dawn Horizon Corps. During a hard fight against unequal odds, Gjallarhorn's outer lunar orbit joint fleet Arianrhod also joins the battle. A three-way free-for-all begins between Tekkadan, the Arianrhod fleet, and the Dawn Horizon Corps.

Mikazuki and Orga visit Allium, leader of the ideological group Terra Liberionis, to resolve the issues surrounding the attacks of the Dawn Horizon Corps. Meanwhile, McGillis arrives at Gjallarhorn's Martian branch, and he offers Tekkadan a certain proposal.

Tekkadan's Earth branch, which is now serving as a military advisor to Arbrau, is consumed with preparing the launch ceremony for the Arbrau Defense Forces. At Makanai's request, Tekkadan takes charge of security for the ceremony venue. But with the sound of an explosion, black smoke rises from the site.

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 day after day.

Gjallarhorn has received 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.

Mikazuki faces off against the mobile armor. The battle continues with mounting intensity.

Lafter and the other Turbines members take their leave of Tekkadan. Meanwhile, at Teiwaz, the organization's number two Jasley Donomikols plans a new maneuver.

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.

With the repairs to the Barbatos complete, Tekkadan musters its fighting strength. The members ready their resolve for the confrontation with Jasley.

Gjallarhorn's Earth headquarters has been captured in a coup d'etat 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'etat.

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 plans to return to its Martian headquarters and start over. The situation, however, has undergone a dramatic reversal.

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

Gjallarhorn intends to launch a mopping-up operation against Tekkadan. The hour of its commencement is drawing steadily closer…

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