Even with San Diego occupied by the Mexican Army, Katarina Sosabowski pursues her MBA at UCSD, and is happy to welcome and put up her visiting step-cousin from Japan, Christopher Dennou, for a night so he can complete his enrollment the following day. But a minor earthquake brings a major surprise: Chris's younger sister, Maya, murders their mother and escapes Neuroi Institute, the research facility that created them. While Chris and 'Cat' grow closer to one another, Maya inexorably crosses an ocean and half a continent to take back her brother, killing anyone who gets in her way.