Vivian, a deadly assassin posing as a high-society escort, Tre, a technician harboring feelings for the ghost of her former lover, and Naomi, a survivor held together by machinery and anger, find themselves at the center of an interstellar crisis when a mind-corrupting contagion threatens to sweep through the galaxy. As they are pulled together by chance and necessity, each must confront their own dark pasts and grapple with newfound bonds that are tested in their fight against a seemingly omnipotent force and the darkness within themselves.