300 years after a great conflict between Earth and Mars known as the "Calamity War," a woman named Kudelia sets out on a journey to Earth to speak for the independence of the Martian city of Chryse , which is under the control of the Earth government. Escorting her are members of the private security company CGS , Mikazuki Augus and Orga Itsuka . When a group named Gjallarhorn attacks CGS and Kudelia, Orga sees this as a chance to rebel against CGS and launch a coup. Mikazuki and Orga are thrust into a new conflict. To fend off Gjallarhorn, Mikazuki rides an old mobile suit from the Calamity War, powered by two Ahab reactors, the Gundam Barbatos .
