When S.T.A.R.S. Bravo Team's helicopter goes down in the Arklay Mountains during a series-of-murders investigation, the Alpha Team is scrambled to find them. Landing near the wreckage, the Alphas are immediately set upon by zombified Dobermans—one team member is killed before the rest manage to reach shelter in a nearby mansion. What seems like a refuge turns out to be far more dangerous than the forest outside, and the survivors must now unravel the source of the outbreak to have any hope of escaping alive.