Finally, after an intense battle with the mob just to get to the promised safe haven, the destination is finally reached and you find out that it is everything that was promised. Now, the center wants you to help them to gather more survivors and get more supplies (food and ammo). You know that this would not be easy, but it is your way of thanking them for saving you from the disaster. The world now is filled with danger and you know how dangerous can it be, so you want to help others. In order to save them, you need to get out there and retrieve some supplies and people.
The Idea here is to save some people on the post-apocalyptic times. This would be dangerous as there are lots of bad guys that are out to get you. You need to shoot them fast and hard. You get money from every kill, so try to kill them all. You can use the money to upgrade your car.