Ten years after the zombie outbreak, Circe and her younger sister Calliope were forced to move into the wrecked city of Guan after their hidden village was discovered and destroyed by the armies of the New People's Federation. There, the sisters are thrown into a ruthless game called "Survival of the Fittest", where players must battle not only each other, but the undead that haunt every shadowed street. Determined to live, Circe makes a choice: to survive, she must be willing to kill. In this world, hesitation is death. Only the fittest survive-and Circe is prepared to prove she is one of them. "She who is fittest, survives."