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).