Entanglement - Turret Strategy:

The second half of Entanglement involves defeating waves of Combine troops, using turrets. A great strategy is to pool them, rather than leave them behind.

The first time you use turrets, it's in a large guardroom at the top of two staircases. There are two turrets here. Set both up to overlook the right hand side, and take the left with your shotgun. It's quite easy.

Collect the turrets and take them with you, moving them up the corridor a bit at a time, then going back for the other one. Quicksave regularly, so you can reload if something happens to cause you to lose one. You'll descend into the sewers where an electric cable has charged the water, so you'll have to make your way across the pipes. Drop the turrets into the water and make your way along the pipes, until you're ready to jump to the far platform. Use the Gravity Gun to collect them again and throw them onto the platform, then jump across yourself. The next bit involves reaching the raised ledge. Throw the turrets over to the other side, then throw all the blue barrels, the wooden pallet and the crate into the water to make a bridge across and use the crate to climb up onto the ledge.

Bring the two turrets through the door and continue on. You should have no problems til you reach the upstairs area with the two doorways and railings. There'll be an office behind you full of random furniture, and the staircase you ascended to reach the part you're on. Take one turret and set it up on the left balcony, on the left hand side, so it covers the hallway/cells below. Take the other turret and set it up on the right balcony, again, covering the hallway and cells below.

Next, use the Gravity Gun to collect the 3 crates from the right hand hallway and bring them up onto the level you're on. Build these up to close up the right hand doorway, so the turret is protected and can no longer be accessed, but can still cover the hallway below.

Repeat the blockade strategy for the left hand doorway, using the filing cabinets and table from the office to close up the doorway, but make sure you're on the left hand balcony when you close it up. Once you've done this and both turrets are set up and ready, jump over the balcony to the hall below and quicksave. Alyx will tell you she sees Combines approaching. Quickly go into the room on the right, and get the other 3 turrets from the holding area. Set all 3 up in the right hand hallway. Put 2 in the middle of the hall pointing up the hall at the forcefield at the end of the hall, locating them just before the shortcut between halls so they cover the end of the hall and any Combines coming through the shortcut, and put the other one nearby facing the other direction towards the turret on the balcony. This should now be sufficient protection to survive the entire attack easily. Just hide into the left of the computer console against the right wall and kill any Combines who get through your defences. I lost about 10-12 health altogether using this method.

When it's all over, Alyx will rejoin you. Use the Gravity Gun to collect the balcony turrets if they weren't knocked down, and bring all 5 gradually down the staircase. Bring them along the dark tunnel and set them all down just after the bit that breaks off to the right, when you can see the doorway at the end of the hall in the distance. Quicksave and approach the door. The game will load the next section. Turn and use the Gravity Gun to bring all five turrets with you. Set them up in the hallway beyond the door. The lights are about to go out. If you get at least two set up, they will kill all the Combines who attack in the darkness. Proceed down the staircase with your five turrets. You'll reach a long hall and Alyx will go through a massive doorway and turn and face you. This is a level changing bit where you can be seperated from your five turrets, so shoot them all through the door behind Alyx using the Gravity Gun, then run through and she'll shut the door. The next bit involves Alyx going through with the other doctor into the teleporter area at the back. Be aware of another door that will close behind you as you walk through. Alyx stands just beyond it to mark where it is. Shoot all five turrets through it into the room beyond, being careful not to shoot them through the forcefields.

This is the final section of Entanglement. If you've followed this strategy, you'll have 8 turrets to set up around the room and won't be shot at once, when Alyx unlocks the other 3 in the corner for you to use. For one last turret use, take one with you when she powers up the teleporter and walk backwards into it. You'll lift it up and it will shoot at the soldiers as you ascend.