Find the Control Room

This level is relatively short, but the first portion can be a complete pain in the ass. But we've concocted a method to get you past without firing a single shot. More on that later. For now, follow the cliff edge through a tunnel to find the control room building in a huge field.

As you explore the field, a ton of Flood will drop in from the sky and rain on your parade. However, despite their numbers, they are not infinite, so it's definitely worth your while to kill them -- actually, scratch that, it's well worth the Arbiter's time to kill them. For you see, since the Arbiter has infinite bullets and can't die, he acts as a mobile battle tank, killing anything that crosses his path. As such, use him as a human shield.and let him take care of all the hard work, but keep your melee finger at the ready in case a foe gets too close for comfort.

You'll have to climb a series of hills and ramps to reach the control room at the top of the building. The first hill is located on the right side of the building. Remember to stay near the arbiter whenever enemies drop in and let him take care of the dirty work. Push forward slowly to activate more enemies, then retreat to the Arbiter for cover. Repeat this as you work your way up the snow-covered hill to the building's first walkway.

As soon as you step foot on the walkway, a horde of Flood will drop in and they're armed to the teeth with guns and rocket launchers. Run back down the hill and let the arbiter and flying sentinels deal with them. Once clear, head back up and follow the walkway, but keep your sword at the ready for any Flood that may appear.

As you reach the first hallway, several more Flood will drop in behind you. Let the Arbiter deal with them, while you tackle a few ahead, in conjunction with Sgt. Johnson who's providing support from a nearby cliff, then continue to a ramp.

After climbing the second ramp, follow the walkway and climb a third ramp up to a locked door.

Guilty Spark won't open the door until all the Flood are killed, so get your sword or shotgun ready. Grab the invincibility from underneath the overhang )opposite the door) and remain here and pummel the enemy's as they come to you. Use the Arbiter as a human shield and deploy the invincibility if you begin taking heavy damage.

Now just continue through the hall to eventually meet up with Guilty Spark.

Kill the Monitor, Activate Halo

Guilty Spark may be the easiest boss in any game. He only has two attacks, one of which is harmless. Just keep your distance and shoot at him, while side-stepping the laser. After enough damage, he'll go down

When he's down, grab the Spartan Laser from Sgt. Johnson and use it on Guilty Spark. Three charged shots should take him down.

Get to the Frigate

With Guilty Spark destroyed, run back through the halls to the exit leading outside (skip past the Flood, as the Arbiter will deal with them). When at the exit, wait inside for two sentinel droids to float past. If you keep waiting, a single flood will usually take them out, if not, shoot them down. Now run up the snowy bank, right of the door, and let the Arbiter take the lead. Follow him around the snowy ledge to a door, as he takes down everything in sight.

Just dart through the hall, past the Flood. However, when you come across the stretch containing numerous carrier forms, stick to the left wall to find an adjacent hall that'll allow you to skip past them. Turn left ahead and continue out to find a Warthog. Drive it down the path and follow the snow bank to the right, past the large exploding section to a large portion of Halo, still under construction.

Now this is where the action kicks into high gear. Essentially, you just have to follow the Nav Points without falling through the crumbling floor. You will come across a few Flood along the way, but ignore them completely, as they're virtually harmless. Also, while it may seem that you have to hustle before Halo's destroyed, worry not - there's no actual time limit, so take as much time as you need. Oh, and when you reach the final jump, go as fast as you can!