It is 1983. The Cold War is in full swing, and humanity faces an attack. Strange aliens, dubbed "BETA," have descended upon Earth with the aim of wiping out all life. Soldiers are tasked with piloting large combat suits known as Tactical Surface Fighters (TSF) to repel the alien invaders, yet the front line is gradually being pushed back toward the surviving cities. Schwarzesmarken follows Second Lieutenant Theodor Eberbach and the other members of the 666th TSF squadron, a ruthless unit that prioritizes mission completion over human life. Stationed in East Germany and commanded by war hero Captain Irisdina Bernhard, the unit specializes in counterassault attacks against laser-class BETA. However, the 666th squadron encounters more enemies than just the alien forces when optimistic rookie Katia Waldheim joins the unit, attracting the attention of East Germany's secret police, the Stasi.