The base has spotted an illegal trading business on the airport and they have sent you alone to the location to eliminate them. You have to eliminate all of the dirty armies and stay alive to complete this mission.
It's a nightmare. You are trapped in an abandoned mine with an injured comrade at your side against God-knows-what. Make your stand, get out alive. Three words of advice: shoot to kill. These things are not human, they are monsters..
Learn how to be a true Cowboy by going through Cowboy School's rigorous tests and tasks. Your shooting skills will be tested to the max, so make sure you try to hit all your targets.