After you’ve talked to Pat Denton, your objective is to kill the Indians that attack the railroad bridge. First head down the cliff path and shoot the Indians, with whatever weapon you deem fit. Close range - shotgun, Medium to long range - rifle. When you reach the other side, head down the cliff path again and kill the Indians, again. Once you have done that wait for the “transport” to arrive, to take you over to the other side. Important: DO NOT SHOOT THE TNT BARRELS or you will fail the mission, it is best to throw them off the side when you can, while remembering to kill the Indians that will climb over the sides of the bridge. Once that is done you will need to get back on the “transport” but be warned, you will get attacked while you are on it, once you reach the other side kill the remaining enemies. Head back up the path to the top for another cut scene. All you now have to do now is protect the Chinese workers and Pat Denton, from the Indians. Remember to switch your weapons for efficiency. Next, you have to use quick draw to shoot the fire arrows in the air, before they hit the TNT barrels. You will also receive some attacks by Indians that will run directly towards you, shoot the torch bearers first with quick draw. When they are dead you have to kill “Quick Killer,” it is best to just shoot him in the head, and using quick draw helps. Remember not to shoot the TNT yourself, and the achievement will unlock when “Quick Killer” is dead.