Half-Life 2 Walkthrough - Chapter 11: Follow Freeman - One Big Raid
The latest part of the fight for City 17 requires your service in the raid on the Overwatch headquarters. This battle will require you to fight through waves of enemies, survive an ambush, and knock out 3 generators. If you need any help, then just look at this part of the Half-Life 2 walkthrough.
Entering the Headquarters
You should be in the make-shift jail and close enough to the building that they can't use the suppressor. Go outside and run to the front of the bank. Kill the few guards in front and then get ready for a bigger fight. The doors explode and a lot of Combine rush out. There are about six Combine soldiers and two elites here. Feel free to use the Submachine gun's grenade launcher or the AR2's energy ball to thin the crowd quickly. You will usually find AR2 ammo on the elites, so you don't have to be conservative. The pillars around the bank make for good cover, so just play conservatively and fight through them.
Once they're dead, go forward to the other side of the street by the forcefield. Use the gravity gun to pull its plug and use the health charger to heal up. Go through the door when you're ready to raid the bank itself.
Those blue tripwires ahead will set off the turret hidden in the floor. This is just a practice one, so don't worry. Grab some grenades and suit energy from closet and then set off the tripwires. Stick to the left wall though. The turret faces to the right and primarily covers the security panel. Just stay out of the kill zone. Then use the alternative fire to drop a grenade right into the turret bay.
Barney will open the doors on a surprisingly empty main room. Go ahead and look around for a bit. The only opening is at the far end next to the gaping hallway with the forcefield. Wait here for a second though. There are two Combine coming into the main room from that same dark hallway on the first floor. Just wait a few second for them to round the corner, then kill them with the AR2. It's a real pain if they manage to ambush you.
The First Generator
The turret room ahead is hard. Tripping the first tripwire will cause one turret right in front of the door to raise. It covers the entrance quite well. There's also a second one inside the room to the right which also covers the entrance and the first turret. You can just wait for the tripwires to reset, which will reset the first turret, but the second one usually pops up regardless. You can also bet that your squad will trip the wires at some point, so you have to kill the turrets. This is one of the hardest turret puzzles to overcome.
Tell your squad to wait in the center of the room. There's no sense in them dying here. Then trip the tripwire and hide behind the door's frame. Take a grenade and try to throw it down the hole. It might take a couple of tries. Once that turret is dead you have two options to kill the one on the right. You can run to the cover of the supply room past the turret and repeat the throwing game, or you can hug the right wall and run out of the turrets kill zone before it opens fire. I chose to run past and then drop in a grenade. Turn to the left and kill the two Combine at the end of the room to the left. Go ahead and get more grenades from the box in the first hallway if you need more. Then go upstairs.
Turn to the room before the tripwires. There are more prisoners inside and you might as well reinforce your squad. Order them to stay in the room and then trip the tripwires. Sprint forward and get to the doorway. If you are really fast, you won't even be shot. The doorway is a huge blind spot for the two turrets. Just drop a grenade into each one and call for your squad. Then enter the room and charge up your health and suit energy. Blast the energy ball with your gravity gun once you're ready.
Backtrack to the stairs and wait by the door. A full squad of Combine just landed and they're coming to attack you. Just wait with the shotgun and ambush the five Combine and the 1 elite when they come through the door to the stairwell.
You have a choice. You can go to the right and have a battle puzzle or go to the left and have an explosives puzzle. I think you're better off going to the right while you have full health.
The Room of Death
Go to the right and cross the bridge. Go into the room through the only open doorway and walk across to the other side until the trap is launched. Both doors are locked and the Combine are preparing a raid. Grab the supplies lying around and then take up a central position with your AR2. Try to kill as many of the passing Combine as you can. They will move down both hallways and shoot through the holes in the wall. Return fire and kill as many as you can. It does reduce the number of Combine you'll have to kill when they breach the doors.
Once they assemble at the top door you'll see sparks start to cut it in half. Drop a hopper in front of it, but don't put it right next to the door. Give it enough clearance to jump out and into the hallway. As the sparks reach the bottom, grab a grenade and get ready to throw it. Once the sparks stop, count to 2 and throw it. It should hit the door, stop, and then explode as they charge into the room. Kill off the survivors with the AR2 or the shotgun. Remember to use the shelves and crates in the room as cover. The first door will start sparking during this raid. Plant another hopper in front of this door and wait. It seems that this side is naturally underpowered due to the rebels' shooting habits. I usually just see two or three Combine alive for the actual raid. Feel free to use the grenade trick again though. Finish off the surviving raiders with the shotgun and then step out of the room.
There are two turrets here. Order your men to wait in the room you just defended and make sure you have two grenades. I believe it is possible to use the radiator on the wall as a shield, but your decreased speed negates the minor protection. I suggest that you just sprint straight through the tripwires and get into the dead zone between the two turrets. Toss a grenade into each one and then enter the generator room. Regroup and use the health charger on the wall. Blast the energy ball with the gravity gun when you're ready to go.
An Explosive Situation
Backtrack out and go to the other room on the left side. Look to the left and notice the tripwires. You don't have to kill this floor turret, but you can get a lot of supplies if you do. It's really easy too. Just crouch behind that large metal desk and walk forward until you trip the turret. Then pickup the big desk with your gravity gun and use it as a shield. Walk forward and set it down right in front of the turret. You don't even have to use a grenade, since its entire field of fire will be blocked. Walk behind it and grab the supplies. Then go back to the hallway near the entrance and entire the room with all the tripwires.
If you set off any of these tripwires, a bunch of turrets in the ceiling will activate and rip you to shreds. So...don't trip any of the tripwires. Pick up the first hopper to disarm it. Then jump onto the one block in front of you and then up onto the higher block on the corner. Walk past the first set of lasers and get onto the curved block in the floor. Look ahead. There is a tight triangle of lasers on the floor. It's possible to jump straight ahead and over the grouping, but the painting on the wall usually falls off and triggers the lasers. Jump for the little triangular safe zone in the middle. Then get onto the circular block and climb a little higher. Get on the pipe on the wall and use that as a jumping off point to get onto the bookshelves. Go to the edge of the bookshelves and see if you can pull up the two hoppers to clear the path for your squad later. Go across the bookshelves to the other side of the room and get onto the pipes. Then just drop down by the health charger. Heal yourself, grab the supplies, and then press the button to kill the lasers. Barney will come in with your surviving squad members. Exit and go forward a bit to get to the generator room. Blast the energy ball and get ready for a bigger fight on the way out.