Part 7

Exit the building and head up the stairs to your left. Turn left at the top to find Cog Tag 3 (CT3).

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

After clearing the enemies, head north. A Raiven will land, and the gate will fall. Touching the gate triggers a cutscene, completing Chapter 1 of Act 1. If playing co-op, you should earn the Dom-Curious Achievement.

After the cutscene for 'Trial by Fire', take cover behind the sandbags. The incoming Locusts are likely handled by a chopper, but you can shoot them if desired.

Head up the stairs and through the door into the next open area.

Take cover behind the second broken wall from the hallway exit. Eliminate the appearing enemies. Use the chainsaw if they get too close.

After killing all enemies, hop over the short wall and then the next one to find Cog Tag 4 (CT4) on the ground in a small courtyard. Do not go up the steps if you missed them.

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 to the left of the small wall where teammates might hide.

Move around the pillar and to the next one. Shoot any Grubs you see. Use pillars for cover if enemies advance, but find better cover if necessary.

Be aware of Locust-holes, which can appear anywhere outdoors. Throwing a grenade into a hole closes it. On Casual, you can try to plug them. On Hardcore, it's often easier to pick off enemies from a distance with a Lancer. If struggling, fall back or try to plug the hole.

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

Use the small wall straight up from the opening as cover. Shoot enemies from afar, and chainsaw them if they get close or attempt to flank. Dying here resets you to the staircase.

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

Wait for Kim to open the door after the dialogue.

Inside, hide behind the first small, diagonal wall. Shoot enemies, who often hide behind pillars.

When an Emergence hole appears (marked by a collapsing statue), run to it, plug it quickly, and return to cover to eliminate remaining enemies.

After clearing the area, head north from the first Emergence hole, around a pillar.

Try to plug the next hole, using the short wall for cover.

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