Part 7

Exit the initial area and head up the stairs to your left. Turn left at the top to find Cog tag CT3.

Engage the enemies. Taking cover behind the small wall to the right of the door leading outside is recommended.

After clearing the enemies, head north. A Raiven will fly over and land, causing a gate to fall. A cutscene will play, marking the end of Chapter 1 of Act 1. If playing co-op, the 'Dom-Curious' Achievement should unlock.

After the cutscene for 'Trial by Fire', take cover behind the sandbags. The incoming Locusts are likely to be taken out by a chopper.

Head up the stairs and through the door at the top. Enter the next open area and take cover behind the broken square (the second wall from the hallway exit).

Pick off the appearing enemies. If any get close, use the chainsaw. This is a good time to test the chainsaw if playing on Casual.

After killing all enemies, hop over the short wall and then the next one. Find Cog tag CT4 on the ground in the small courtyard.

Proceed up the next set of steps. A short, unskippable cutscene will play.

Your teammates will instruct you to flank the Grubs. Take cover behind the first pillar (with an ammo box in front of it) to the left of the small wall.

Move around the pillar and to the next one. Shoot any Grubs you see. On harder difficulties, use the pillars for cover, but be prepared to move if they advance.

An Emergence hole may appear. If outdoors, these holes can spawn enemies. Throwing a grenade into the hole will close it. On Casual, you can try to plug it. On Hardcore, it's often easier to pick off enemies from a distance with a Lancer. If desperate, fall back and let enemies come to you, or attempt to plug the hole.

After killing all Locusts, head left of the Emergence hole to a white collapsed pillar. Behind it is a box. To the left of the box is an open gate.

Use the small wall directly up from the opening as cover. Shoot enemies from afar, and use the chainsaw if they get close or attempt to flank you. If you die, you will restart from the staircase.

Head directly north to a bridge. At a broken segment, press Y to see Cog bodies.

Wait for Kim to open the door. Once inside, hide behind the first small, diagonal wall you see.

Shoot the enemies, who often hide behind pillars. When you hear an Emergence hole, run to it (a statue above it may collapse), plug it quickly, and return to cover to eliminate remaining enemies.

After eliminating everyone, head north from the first Emergence hole to go around a pillar. Try to plug the hole by hiding behind the short wall.

Remain behind one of the two pillars behind you and take out any remaining Locusts.