Quarantine Zone/Walkthrough

Objects in the Mirror Are Larger Than They Appear
After the cutscene you'll see a Ghost to your northwest. Get in before the Special Operations Elite in front of it does. Once you're inside, look straight ahead. There will be a hill and a way to get on top, go about a 4th of the way up and wait for an Enforcer come straight out of the large opening in the wall. It'll go straight if you stay still. When he starts to turn go up and make a left turn into the door. Follow the path until you reach the 2nd door. When the music starts to play, go right. A Sentinel will attack you but ignore it and drive past the pillar in front of you. Watch out for the Flood-controlled Scorpion tank. Make another right down a ramp then make a left and go through the door ahead but wait for a Flood driven warthog to come through first.

Then go through the tunnel until the next door. Up ahead you'll see two turns. Take the right one. Head downward until you see two "closed" doors. Go through whichever and as you get closer the door will open. Up ahead, make a left turn through a cave. At the end of the cave make a right turn and proceed until you come to a topless tunnel wait until you see a flood combat form shoot a rocket. Find that flood and run it over (do this fast because ghosts will then ambush you). Once you do that find a land bridge (direction varies from which angle you killed the Flood) and go over it then head straight into an ice cave.

Go straight past the silhouette of a Scorpion go straight until you're about to hit a dead end and turn left. You'll see what looks like a barricade crash into it and get out of your ghost go through the barricade and through the next cave until you see more ruins make a right and go up a ramp go straight until you hit the wall then go left until you're in a corner and with your carbine destroy however many Sentinels are shooting at you. Let your shields recharge and then go spec ops.

After that jump off the ledge in front of you face right and go straight just go straight until you fall off another ledge then face right again and go straight. Something will fall in front of you that's on fire when that happens walk up to it and face left walk off the edge in front of you and pull out your energy sword then return to spec ops find a cave with combat Flood coming out of it then follow it to what looks like a dead end then turn left. Go straight an go up then where the pillars are get up there and go find a cave inhabited by Sentinels, and go straight.

Once your out in the snow go past the wraith to an empty space of land on a cliff. Then wait for it drop a Spectre and two elites get in the driver seat and go towards where you came from but to the left go straight past the wraith and over a small ledge then go left again. Go straight off the ledge ahead but slower you want to land thge jump. Now go to your left and around the green pit then go past the scorpion tank and to the lights go right and get out now go through a door until you find another opening and go up the ramp to what looks like a bigger version of the Gondolas you rode on Regret. Then watch the cutscene.

Shooting Gallery
Get ready to battle the Flood with your sword, and protect your men, but this part is relatively easy if you pay attention. Replace your sword whenever necessary--but do not wait until it's depleted. Instead, give the near-empty sword to a SpecOps Elite. By the end of the ride, all the (remaining) Elites should have swords. However, If your men die, don't fight. Take cover because the Flood will think you are all dead. Just wait; patience is the key. Tartarus will then say "The Humans are inside, Arbiter. After them!" This means the ride is almost done. When it stops, go to the front of the Gondola and walk onto the ramp. Go down the right side and go straight. Without shooting anything, just keep walking, and eventually you come to a dead end. Go left and back just a bit, and go through that opening and watch the level ending cutscene. Congratulations, you have made it through the Quarantine Zone alive (even if you have ended up being hurled over the edge of a platform by someone you believed to be on your side).

Objects In Mirror are Larger than They Appear
Grab a Ghost (see Speed Run Walkthrough unless you want a Scorpion) or a Spectre, whichever you prefer. Be ready to face an Enforcer as the door opens. If you have a Spectre, let your gunner do the work. If you are in a Ghost, rush past it before it can pick you up.

Take either the left or the right path. If you want an 808, go right, off the ledge, and quickly splatter the Combat Form before it gets in the tank. Then take your new ride and kill everything in sight (but check your fire after a few moments, because reinforcements will come. Whatever you do, go through the door at the back, but watch out for a Warthog.  Don't drive directly under an Enforcer because it will pick you up.

Healthy Competition
Kill all of the Enforcers and Sentinels in this area, then proceed.

Go to the left and at the 90 degree right turn, get out and kill the Flood manually. There is a rocket-armed Combat Form who will lock on. Two hits will kill an intact Scorpion. Be ready for two Ghosts.

Continue, destroy any Wraiths, then enter the destroyed Sentinel Constructor Factory.

Lay waste to the Scorpion, the Wraith, and any Enforcers. Get out of your Spectre or tank and proceed on foot.

Wait out the fight, then mop up the survivors with your Carbine (or whatever you picked up).

Enter the next section, ignore the Enforcer (you don't have any heavy weapons), then proceed. Watch out for Combat Forms and Sentinel Majors. Disappear as you enter the tunnel at the far end and run past the Flood.

Stay to the right and proceed to the cache of human weapons. Pick up a Rocket Launcher if you would like. Avoid the Wraith. Keep going hard left to get the Ghost. If you would prefer a Scorpion, there is one at the far left corner of this area. Use your 90mm cannon to destroy the Wraith or your Ghost boost to rush past it.

Turn hard right and drive down the area. There is a Warthog, then a Gauss Warthog, so be careful. Go under the arch to your right, avoid or destroy the Wraith (whichever is more appropriate for your vehicle), then go behind the wall. Many of the Flood here have MGs, so destroy the emplacements or rush past. Go through the hallway (you may need to leave your vehicle) and choose left or right. Continue to the end.

Shooting Gallery
Give one of your Elites the rocket launcher if you have it, then slash any Flood that drop onto your gondola. If you find a stronghold around the corner (6 Flood or more), throw grenades to lighten the resistance. When your Energy Sword runs out, pick up a shotgun or another sword.

That Old, Familiar Feeling
When the gondola reaches the end, go to the left end of the platform and follow the large hall to the right. There is a short corridor to the end of the level.

Objects In Mirror are Larger than They Appear
Grab a Ghost. Rush past the Enforcer and the first section. Don't worry about shooting anything. Use the nose raise (press the jump button) to quickly drop down.

Healthy Competition
Rush in the same manner as the Legendary Walkthrough, but don't get out—try to outrun the rocket Flood and the Wraiths.

When you get to the point where you must get out, use the nose raise and the boost to force your Ghost through the barrier.

Rush quickly to the left of the first room, then continue forward to the outdoor section. Rush to the back, then drive through the short tunnel and up the ramp. Evade the Flood attacks, but don't try to splatter.

At the weapons cache, get out and quickly run for the Ghost.

Shooting Gallery
You cannot control time spent on this section, so complete it as normal. But be ready to get out right when the gondola reaches the end.

That Old, Familiar Feeling
Continue as you normally would.

Healthy Competition
Rush through these two sections as in the normal Speed Run Walkthrough, but when you reach the weapons cache, quickly run for the Ghost without shooting anything.

Shooting Gallery
Go to the back of the gondola. Get on the barrier, then crouch-jump to the flat part of the axial beam cutout. Run up the beam, and you will glitch through two walls. Stay on your invisible platform as the gondola moves.

When you get very near the end (be careful not to get too close), jump over the barrier in front of you.

That Old, Familiar Feeling
Continue as you normally would.