In the distant future, the surface of Earth has been laid waste thanks to a deadly pathogen known as the Punishing Virus. With little chance of survival, what was left of humanity was forced to retreat to a space station suspended in low-Earth orbit called Babylonia. The human residents of Babylonia then developed technology that allowed them to transform human soldiers into modified beings known as Constructs. These construct soldiers, along with their human Commandants, now serve as the final bastion of hope for humanity's survival in the fight against the Punishing Virus.

The Gray Raven squad takes center stage here. Lead them, befriend them, fight them. The world is your oyster.