In C.E. 73, tensions between Naturals and Coordinators continue to persist, eventually leading to another war between the Earth Alliance and PLANT. Sven Cal Bayan is a Natural pilot of the elite EA squad, the Phantom Pain, and carries out his squad's various anti-Coordinator missions without fail. Selene McGriff is a Coordinator researcher at the neutral Deep Space Survey and Development Organization (DSSD) and a developer of the GSX-401FW Stargazer space exploration mobile suit. Though their backgrounds are completely different, the expanding war will nevertheless force their paths to collide.