Your mission was to get Murphy, a man with the antibodies for the zombie virus in his blood, to a CDC lab in California. You had completed your mission, until Murphy took down the submarine and took their doctor, taking 10K (a sniper) with him. He was now set up in Spokane, making an entire race of half zombie half human hybrids, and setting up an empire, while being an arrogant dick in the process. Now it was you, Warren, Doc, Hector and Mack, trying to get Murphy, and 10K, back.