This is where it starts to get harder, in that you have to move more slowly and take your time. You learn that Captian Keyes has been captured and you have to go rescue him. You do the first phase of this mission on the ground, getting to the place that sucks you up into the ship.

You begin with a sniper rifle that has night vision. Be sure to turn on night vision and the zoom-in, and sneak forward. You should be able to kill off quite a number of them easily. You have to reload often, so be prepared. Get them all including any that sneak towards the turret.

Head left around to another turret. Follow the path around the cliff, sneaking forward slowly and sniping them.

Now you end up in an open area with a few turrets and get into a large battle with everybody. You may have to stop sniping in here and just blast them away. When you clear everybody out, there's a narrow corridor in the cliff wall that leads towards the upload area. You can see it if you look towards the 0 in the ship overhead.

You have to fight a ton here too, and get onto the blue area. Reinforcements will come down at this point.

Master Halo Walkthrough