There were 18 names on the kill-list of Walter David Scott during his killing spree of 2009, only 17 of which he was able to cross off. Sarah Prince, the eighteenth name on Walter's list, was able to escape his grasp and orchestrate his capture. Seven years later, her testimony seals Walter's fate: death by lethal injection. Sarah's nightmare is finally over...or so she thinks. A year after Walter's execution, a tech genius unveils the Exodus Portal, a virtual reality environment housing a cutting-edge artificial intelligence, meant to give its users a true survival horror experience. Sarah, along with seven other participants, agrees to take part in the first public run of the game, but when the A.I. unexpectedly starts to exhibit the same behaviours as Walter, the group is mysteriously expelled from the Portal.When members of the trial run start turning up dead in the real world, the group worries a copycat killer has surfaced. Sarah, however, fears something far more sinister: that something familiar has followed them out of the Portal...