Key of Z — Claudio Sanchez

From the creators of The Amory Wars saga and Kill Audio comes a new vision of New York City! The zombie apocalypse has transformed the city into two battle-hardened fiefdoms, controlled by twin warring factions! One man, whose family has been ripped away from him, stands between these two superpowers. With power drawn from an artifact from better days, his quest for vengeance starts now!