Zombies at the Bridge
Nobody knows what started the plague, but all we know is that somehow we need to survive. There was no hope for the fist and the second town, but those zombies need to cross the bridge to get to the next town and we can do something about that. The government place some wall in the bridge to prevent the zombies from entering, but their number grew and we need to get rid of them. A few marines came blocking entrance to the town. You are assign in the bridge to intercept the zombies. Shoot those zombies down before they can destroy the wall.