At first this mission may seem difficult, but it really is not. In the first part, get your bow ready. Every time Magruder is eater next to or on top of the holes in the ground with the blue green gas coming out of the floor, shoot an arrow into it. When it blows up, it will take some health from Magruder. This will take a few times. To better judge where Magruder is, look on your radar when you are standing by one of the holes on the floor with the blue green gas. When you see a red arrow by you and it is near the hole in the floor, shoot the arrow. When it explodes, run. If you take some hits from Magruder, run for a flask to repent your health. You will most likely run out of arrows, but can find more in the back by the big entranceway opposite of the platform and big pillars that you will need to destroy in the second part of the mission. Keep shooting the arrows at the gas in the floor until Magruder's health bar turns red. After that the second part of the mission begins. To save a lot of your health during the first part, crouch and stay near the outer ring of rocks. If he stands directly in front of you, shoot about one or two arrows at his feet. This will cause him to lose health. If you got hit by his fire, run and find a flask. The second part of the mission is to collapse the cavern on Magruder. Save the game when you get to this part. Do not worry about replenishing your ammunition. Your sniper rifle, regular rifle, and six shooters will suffice. In order to keep one flask and your health to where you do not need to replenish, stay ducked behind the big rocks where you start. Magruder will throw TNT. Use Quick Draw and shoot the TNT. Then, pull out one of your rifles. Use the sights on them. The only way you are going to get Magruder to throw TNT is to hit him in the head. However, it is recommended that you stay and shoot at him from the right hand side of the rocks. That gives you more cover than the left hand side. The trick is how skilled you are at Quick Draw. This is the only way to get past it this part of the mission. Try to hit all the TNT when he throws it. Try hitting the TNT that looks pudgy -- they provide a bigger boom. The small TNT sticks are good, for when hit they will spread out. You can blow the two pillars by Magruder's platform up with them. When he says you are blowing this mine apart, you are half way there. When Cole says there is no one left to help you, the mission is about over. When he throws the three sticks of TNT and you miss and they land by you, run to the opposite side, and then go back to continue. You have two big rocks to blow up to collapse the cavern. The best way to do this is to hit the TNT when it is thrown when they are close to the rocks above Maruder. By doing this you will complete the mission faster. When the second big rock falls, the mission is over and you have completed the game.