All your team members are dead and you're the only one survived. Just stay alive as long as you can and don't forget you are low on ammo, use 'em wisely.
Defend the hill against all mindless zombies that assumed it to be their home. Use 19 powerful weapons including the hand cannon, hunter pistol and the jackhammer to destroy them.
Strike down the enemies once again with a pistol or a sniper rifle. Don't forget to shoot the bomb within 2 seconds otherwise it'll explode and damage your health.