You'll begin the chapter in the middle of a garbage heap. Follow Rico and do as he instructs: Shoot the explosive barrel to clear a path to Narville and the rest of the ISA.
Rico will split up, leaving you with only paper thin ISA soldiers guarding your back. Grab a rifle and snipe the enemies off in the distance, particularly those with sniper rifles and rocket launchers. Soon a platoon of ISA tanks will arrive and roll over the remaining Helghast.
You'll meet back up with Rico and will have to guard a control tower at the far end. Use your rifle to clear auto the first wave of guards and then switch to a closer range weapon. Drones will start coming in, so be ready to hit them hard with a shot gun or assault rifle. As long as you stay on top of the tower, the enemy will tend to take the ladders up to your level. Use this time to shoot them while they climb and help out Rico as needed.
After about three different waves of enemies and drop ship delivery, Rico will have enough workspace to start up the crane. He'll swing over a pile of garbage that you may detonate to move through the next gate.
Here you will do battle with a gatling gun boss and several respawning cronies. Take out the lesser enemies first while Rico distracts the boss. The big foe's pathing is rather shoddy, and will often get caught on the terrain. Use this flaw to pelt him with rifle fire to the head. Eventually the boss will hunch over, giving you a free shot to blow up the tank on his backside.
Enter the building and you will find some really poor cover. Even while hiding behind this the enemy above can quickly turn your brain into Swiss cheese. Instead dash to the hallway on the right and charge through the Helghast that try to block you. Swing around the room counter clock-wise and take down each enemy in the way. Rendezvous with Rico and take out the lone roof enemy before pressing on.
Many of the Helghast are armed with rocket launchers, but aren't quick enough on the draw to be much of an issue. Stun them with rapid fire from your rifle and move in for a brutal melee
You'll group up with a troop of ISA soldiers that are storming the bridge. Head to the right side of the stairs and help support your allies against the advancing enemies. It's a little risky to go straight to the mounted weapons. Instead, knock off a few enemies first before heading to the heavy weapons.
You'll want to take out the last few enemies at the bottom of the stairwell. There isn't much cover on your end, but the Helghast will pop out one at a time. Head to the bridge and arm up a bomb. Let the ISA troop with you tank the brunt of the forces, while you take down the remains from afar.