Mobile Suit Gundam 00: Second Season

The Earth Sphere Federation's autonomous peacekeeping force "A-LAWS", has been suppressing an opposition force called "Cataron", using inhuman tactics and extermination. Saji Crossroad has been working as an engineer on the "Proud" Colony, a space station under construction. When a coworker is discovered to belong to Cataron, Saji is arrested under false charges by A-LAWS and pressed into forced labor. Cataron forces mounts a rescue, but A-LAWS mobile suits appear with orders to exterminate the rescuers and all station personnel to cover up its forced labor operation. Setsuna F. Seiei, infiltrates the colony during the battle and rescues Saji. Setsuna then engages the A-LAWS suits in Exia. Still damaged from its battle four years prior, Exia is no match for A-LAWS' new "Ahead" mobile suit. Setsuna is saved at the last moment by the appearance of Tieria in his new Seravee Gundam. Brought back to Celestial Being's new mothership, Ptolemios II, Setsuna is confronted by Saji who now knows Setsuna's identity as a Meister. Once again joining Celestial Being, Setsuna returns to Earth to recruit Lyle Dylandy as the new "Lockon Stratos".

After entrusting Lyle Dylandy with top secret information pertaining to Celestial Being's activities, Setsuna goes to confront Sumeragi Lee Noriega who, consummed by guilt over the countless lives lost during the organization's military interventions four years prior, found refuge in Bill Katagiri and worsened her drinking condition. Meanwhile, Wan Liu Mei leaks information to Ribbons and Saji Crossroad is given access to Celestial Being's archives and learns about the existence of the Throne Gundams. A-LAWS forces mount an attack on Celestial Being's ship, the location of which was among the data acquired by Ribbons, and Tiera is left alone to defend the Ptolemaios. Setsuna, accompanied by Lyle and Sumeragi, heads towards the ship and boards the 00 Gundam, easily dispatching the attacking units and saving the Ptolemaios.

Celestial Being descended to Earth to launch a raid on a Human Reform League-run prison complex, which holds Allelujah and Marina. A-LAWs forces are deployed to back HRL forces in the area to prevent the raid from being successful. Having been given intelligence by Lockon, Kataron guerrillas also assault the prison to rescue their comrades. Though having no experience in mobile suit combat, Lockon manages to display reasonable combat ability. Setsuna secures Allelujah and Marina during the raid. During an encounter between Soma and Allelujah, the latter reveals her true name, Marie Parfacy, before Allelujah boards the Arios.

Marina speaks to Setsuna, Tieria, Ian and Lasse, thanking them for saving her while making a request for them to be bring her back to Azadistan when Tieria refused at first. On the way to Azadistan, the Ptolemaios 2 is attacked by an A-LAWs navy ship in an ambush and has deployed underwater mobile armor 'Trilobyte' to eliminate the ship. Setsuna, Lockon, Tieria and Allelujah have managed to defeat them, bringing the fight to the surface before Soma and The Masked Man intercepted Setsuna and Allelujah with their customized Aheads. Kataron mobile suits arrive just in time to drive back the A-LAWs ship. Marina and Shirin are then reunited. Meanwhile, Billy has been recruited as an A-LAWs MS development chief due to his grudge with Sumeragi.

Setsuna escorts Marina back to Azadistan after the Meisters stop at Kataron's Middle Eastern base. Saji leaves the base as he does not trust the Celestial Being's action. Suddenly, an Earth Federation ship arrives in the area and detains Saji before Sergei decides to release him. An A-LAWs task force arrives with Mr. Bushido, Soma and Barrack leading the squad before automaton droids were deployed to massacre Kataron guerrillas and civilians. Lockon arrives with Tieria and Alelujah to hold back the A-LAWs task force with Lockon gunning down the droids in rage while Soma hesitates to attack him when she sees the droids attack the guerrillas and civilians. Setsuna and Marina arrive in Azadistan, only to face Ali with a mobile suit as he watches the country burning.

After the Meisters land on the damaged Kataron base in the Middle East, they were greeted with accusations and distrust. At this time, Tieria brings Saji back to the Ptolemaios 2 after he spotted him all shaken up in guilt. A-LAWs launches another operation to sortie against the Ptolemaios 2. The Meisters launch to intercept while Sumeragi is out of action after a flashback of a failed operation she led that resulted in her love interest, Emilio's, death. Saji follows Ian to a Ptolemaios 2 turret, while initially hesitating to do so before he fires it at a GN-X III piloted by Louise Harlevy. Allelujah encounters difficulties while facing Soma and Setsuna with Mr. Bushido. As a result, Setsuna goes into trans-am mode with his 00 Gundam.

To break his stalemate against Mr. Bushido, Setsuna takes an extreme risk by activating the 00 Gundam's Trans-am system in order to win. Soma's Ahead and the Arios are shot down and declared MIA as the Ptolemaios 2 is forced to retreat. Stranded and forced to face each other outside their mobile suits, Soma suffers mental attacks from Allelujah's presence and reverts to her Marie personality. Upon finding them, Sergei eventually decides to let them go and the two are rescued by Lockon. Meanwhile, Marina and Katharon learn the Federation intends to reorganize the Middle East and has dissolved all nations including Azadistan.

During his encounter with Regene Regetta, Tieria learns the Innovators' views on VEDA and Aeolia Schenberg while the A-LAWs obtain two new pilots: Patrick Colasour and Innovator Revive Revival. Tieria and Setsuna go undercover to infiltrate a party with A-LAWs and Earth Federation officials, where Tieria meets with Ribbons Almark, who reveals that according to Aeolia's plan, Tieria should have died with the rest of Celestial Being four years ago. Refusing an offer to join the Innovators, Tieria and Setsuna, who has been exposed to Louise as a member of Celestial Being by Billy, escape in their Gundams.

Setsuna and Tieria face off against Ali Al-Saachez’s Arche Gundam, but are sorely outmatched until Allelujah and Lockon arrive and drive off the Arche. Lockon learns the circumstances behind his brother's death and his motivations for fighting for Celestial Being. The A-LAWs attempt to intercept the Ptolemaios II's return to space; the Ptolemaios' success forces Commander Homer Katagiri to accept the help of the Innovators to prevent any more sacrifices. When Kati sends a message to Celestial Being expressing respect for Leesa Kujo's tactics, Sumeragi realizes that Kati is a member of the A-LAWs and recognizes that Sumeragi is Celestial Being's tactical forecaster.