Eliminate Hostile Anti-Air Units

Follow the marines across the cliff edge, through a short cave, to the first enemy base. Continue along the canyon wall to the peak, overlooking the enemy installment, right by the sniper rifle.

Since the enemies are initially unaware of your presence, whip out your sniper and target the Brutes below (aim for headshots!). Crouch behind the boulders for cover if you begin taking heavy fire. If you need more sniper ammunition, collect ammo from the gun behind you for 12 additional shots.

When clear, continue along the canyon wall, and step around the corner slowly (by the tower) and target any additional enemies further up the path. Before continuing, grab the sniper ammo from the weapon capsule in the center of the path, then push through the tunnel.

You'll emerge on a ledge overlooking a second enemy installment. Hang back up here and use the boulder for cover as you use the sniper and battle rifle to shoot the Brutes, the sniper on the building, and others beyond. Once most of them are down, a Phantom will drop off a pair of Hunters.

Note:
Try to retain at least six bullets for your sniper (if not more), as they'll be invaluable later in the level.

Instead of fighting the Hunters, we suggest just running past them and up the path beyond. However, there are several enemies along the ramp, including a Brute at the top, so kill them fast, before the Hunters catch up - a grenade can be very effective here.

Enter the cavern at the top and drop to a door below. Continue through the hall, and out the other side.

Back outside, you should now be on the lip of a large field below. Stay on the ledge, using the rocks for cover, and blast the Brutes and grunts both below, and on the other side. Work your way slowly around this ledge, without dropping into the field below. Once you clear the area, two prowlers with four brutes each will roll in. Most of the Brutes will exit the vehicle and chase after you on foot - toss a few grenades (but try not to destroy the prowler!) if you have them for an easy victory, or hang back by the rocks and shoot them otherwise. By this point, there will likely be two Brutes still rolling around in the second Prowler. We suggest hoping into the first prowler's turret when safe and use it to blast the remaining Brutes.

Once the area's clear, take the driver's seat and let your marines pile on in. Now this part is easy - just drive and don't worry about the enemies; you'll be out of there before they know what happened. Blast over the hill at full speed to clear the jump, then continue up the mountain, going around the fallen ship on the right. After passing the second ship (on the right), you'll drop off a high ledge - stop here.

Normally, you would proceed into the field ahead and work your way to the top of the building, only to discover that you can't actually get in yet. Since there's nothing you can do, skip that part altogether - instead, continue down an adjacent path on the right (just after dropping off the ledge, mentioned above).

Two enemy Ghosts await just past the large boulder, and you'll want to hijack one of them. Drop the prowler off near the rock (so the turret can target the ghosts if they come near), then walk up to that very boulder and circle it for protection. The ghosts will either go after you, or the prowler, drawing them close to the rock either way - continually hold down the Hijack button and try to grab one as it gets close. Now that you have the Ghost, kill the second one, then continue up the path.

There's another group of enemies at the peak. Don't bother shooting them; instead, circle the area and mow the enemies down by boosting into them. If you take heavy damage, seek cover lower down the mountain. However, you will want to shoot the Ghost, and a nearby Brute if he's using a turret.

Once clear, stop inside the cave ahead, overlooking a massive field. Out there awaits a ton of Brutes, several Wraiths, and many Ghosts. Hopefully you still have the sniper rifle (as we mentioned earlier), as it's invaluable during this portion. Stay inside the cave and target the Wraith's gunner first - aim for the head. Once he's down, target the grunts inside two of the nearby turrets (if the circular turret is facing you, fire at it once to scare the grunt away). Finally, target one more turret on a tower to the left (near a group of Brutes).

Note:
If you don't have any remaining sniper ammo (shame on you!), charge up to the rock by the Wraith and use it as a shield while you take down the two turrets with the Ghost. Then quickly hob aboard the Wraith and take it down.

Now boost right up to the Wraith, hop out, and board it. Melee it four times to destroy both it and the driver (unfortunately, it's impossible to hijack this Wraith and drive it around). By this time, several Brutes should be making their way across the land bridge, toward you. Boost across the bridge, running over as many as you can in a single pass.

After trampling the Brutes, two Ghosts will drop in - ignore them for now and quickly return to the cave you were sniping from to lose them (by either going right around the Brute tower, or simply dropping off the left side of the land bridge). By returning to the cave, the Ghosts will likely be roaming about the lower area. Lure them to you, one at a time, and kill them with your Ghost's firepower. Once both are down, return to the fallen Wraith and take down any Brutes who remain.

Now the large rocky structure in the center (just past the fallen Wraith) is home to several more brutes & grunts. Before proceeding though, take down another gunner in the right-most tower. Now edge around the rocky structure, so it can be used as cover, and target the enemies beyond. Go for the turret first, then the Brutes.

Once the area is cleared out, focus your fire on the two nearby anti-air units (if your teammates haven't destroyed them already). As long as you stay behind them, they'll leave you alone.

With the area cleaned out, a gigantic airship will deliver three tanks and a Warthog - yeah baby, this is what we're talking about. Hop into any of the tanks after they've rolled off the platform and work your way back to the wall (in case you skipped it earlier, as we suggested, just follow the path - it'll lead you right to it).

Lead Friendly Armor Through the Wall

Honestly, with the tank's artillery power, you shouldn't need much help backtracking to the wall. For the most part, just fire shells the moment you spot an enemy and stay back as far as you can, within reason, to avoid counter-fire.
As you begin your trek, four Ghosts, and one Prowler will emerge from the cave you were sniping from. As you enter the cave, two Hunters will attack - feed them a shell each.

As you exit the cave, you'll spot a hovering Phantom. Shoot its turret first to render it harmless, then focus on the ground based troops. Continue down the path to encounter a few more Ghosts, then a Wraith. Stay as far back as you can (using the Sand Dunes for cover) and fire a few shells to destroy it. Shoot the tower around the corner, then continue into the field ahead, where the wall awaits.

The entrance is on the top floor of the wall. To get there, follow the path along the left cliff wall. Along the way, you'll encounter a couple of Wraiths and several Ghosts. The Wraiths can be slightly tricky to target, due to their locations. If you can't shoot them from afar, get close and strafe around them while pummeling them with shells.

Push along the path and across the bridge. Keep an eye out for a couple of turrets at the end, then wait for Guilty Spark to open the locked gate and head on through.

Locate the Cartographer

Grab a Brute Shot and/or Sentinel Beam from the high walkway in the center, then drop to the door below. Proceed through it once Guilty Spark opens the way.

Activate the switch on the left platform to spawn a bridge, allowing your comrades below to pass by. Now continue through another door on the opposite end and venture through a couple of rooms to emerge back outside.

As soon as you step outside, a Scarab Tank will climb down and proceed into the valley…is your work never done? Hop into the nearby Warthog and let the ex-driver gun. Now roll on down the mountain, slowly, letting the gunner take down the Ghosts and enemies along the way. You'll soon regroup with the three tanks from earlier - take control of one and proceed onward!

Up ahead are two Wraiths, one on the far left, another on the right. Their aim is poor, so hang back and blast both from afar. Continue on to find two more Wraiths a bit lower. Use the rocky ledges for cover and take them down.

The Scarab will soon make his grand reappearance at the base of the area. But this time, you have a tank on your side. Just circle around him, while shooting continually at a single leg to knock him down - it shouldn't take long.

What if my tank gets destroyed?

If your tank gets destroyed, the best course of action is to simply restart from a checkpoint. If, for whatever reason, that doesn't work, seek out any remaining vehicles that are still in working order. Ghosts are highly effective, followed by Choppers.

Once the Scarab is on the ground, a large loading dock on the back is now within reach of a jump. Quickly run to the rear and jump aboard. Now be careful, and take your time, as there are several enemies aboard. Work your way to the back of the Scarab to find the control room. Melee the shield to destroy it, then melee the console twice more to take it down. Now you only have about 10 seconds to get the hell off the Scarab before it explodes, so move fast.

With the Scarab destroyed, reclaim your tank (or any of the others, if they still exist) and push up the nearby ramp, along the wall. Here you'll find several Brutes and Snipers, but they're no match for your tank. If you lack a tank, or any vehicle, at that, push up the ramp slowly, using the walls for cover. Unfortunately, you'll have to ditch your vehicle near the top in order to continue through a door.

After Guilty Spark opens the door inside, hang back here and blast the enemies within. Once clear, go through the door on the right and follow the halls to another enemy filled room. Stay on the catwalk and follow it around to a Brute's backside for an easy assassination (even though it appears he's looking right at you, he won't notice you if you're quick). Now stay on the walkway and target the grunts below. Once clear, exit out the door, just below the catwalk and follow the ramp down to another door.

Get ready, because a Brute is waiting on the other side of that door. As soon as it opens, run up and melee him twice for a quick kill. Now toss a grenade (if you have one) at either of the two Brutes across the room, then quickly duck into a hallway on the right and take down the jackals. Use this hall for cover as you target the remaining Brutes in the room - use grenades if you have them. Once clear, exit via either of the doors, opposite of where you entered to emerge back outside.

Don't waste time looking at the beautiful waterfalls - activate the switch ahead.

Head Downstairs for Evac

After the cutscene, you'll want to work your way downstairs, to a Pelican landing site. Run through the previous room up to a door on the far side. As soon as it opens, three Brutes will try to break in. Hang back to the side of the doorway and melee them as they step through - remember, Brutes can't counterattack if you melee them non-stop. Proceed down the ramp through another door onto a purple walkway.

Be careful, this room contains several cloaked Brutes. But thankfully, they're not completely invisible. Ignore them for now and follow the walkway to the other side of the room, then drop off and head through the door. Kill the jackals on the ramp, then immediately turn around, as a few Brutes will chase you from the previous room. Melee attacks should do them in. When clear, exit through the door at the ramp's base.

A group of Brutes surround their hammer wielding leader. Needless to say, you're a dead man if you just run in. Instead, follow the walkway up to a weapon cache containing a Carbine, and use it to fire upon the hammer-bearing leader, dropping him in seconds. Stay in this general area as you target the remaining enemies, ducking to the sides for cover. Once everyone's dead, board the Pelican that pulls in to complete the mission.