[Necromancer]

Lowlife

Your goal now is to head through the seemingly endless system of sewers and parking lots underneath City 17 until you can reach the surface again. Theoretically, being underground might be the safest place to be if the Citadel blows up, but you’ve got to risk it - who knows what that Combine communication might mean?

Begin by heading down the turret-overwatched tunnel near the start point of this level. The turrets can’t be destroyed, but don’t worry; they’re out of bullets anyway. Use the bricks and other detritus here to fling at the zombies and kill them, but watch out for mines!

When you find the darkened side corridor here, head to the locked door at the end and blast the vent to crawl into the airducts. After some poking around, you’ll find a ladder which leads into the room on the far side of the locked door. With your flashlight, find the small stash of guns and ammo behind the gate; in order to get them out of the armory, you’ll have to nab them with your gravgun, then drag them up towards the ceiling and bring them through the small gap there. Get the pistol and the shotgun, and use the pistol to shoot the lock off the nearby gate. You’ll find the power console nearby; use it to power it up and let Alyx through.

The Darkened Tunnels

You’re going to reach a completely darkened tunnel here; use your gravgun to push the car in front of the door out of the way. Turn left to find a few more rounds for your boomstick before moving up the tunnel here. The basic mechanic you need to know is that Alyx can’t fire on your target unless she can see it, so keep your flashlight pointed at anything you think needs killing. As you progress, you’ll run into antlions; zap these guys with your gravgun to temporarily stun them and knock them onto their backs, which will let Alyx finish them off a bit more quickly than she normally would be able to.

After hitting a train car that’s somehow impacted its way into the tunnel, you’ll run across your very first zombine: a zombie varient of the Combine soldier. These guys are a lot tougher than your normal zombie, so that they can take a bunch more damage, but will also periodically unclip a grenade and perform a suicide rush on you to try and blow you to smithereens. Do your best to deal with them from a distance, then. When they do run towards you, they’ll move fairly quickly, but will often slow down when they get near you, allowing you to put a couple of shotgun rounds in their head(crab). Between that and Alyx’s firing, they should usually go down.

Of course, in the darkened tunnel near the train, you’re immediately going to run across numerous zombines. Your best bet here might be to get behind one of the cars and use your gravity gun to blast the car into the zombines as they approach; they’ll take a lot of damage, but can usually be killed with a few blunt impacts.

Tip: You see the flares scattered on the ground in this area? Well, if you pick one up with your gravgun and fling it at an enemy, it’ll set them on fire. You won’t do any explosion damage to them, but still, setting them alight is essentially a death sentence, since they’ll automatically die after a little while.

When you reach the end of this tunnel (watch for the barnacles on the ceiling), find the small corridor nearby and flip the switch. That’ll power open a door you passed by earlier, which will let you take some stairs up to another level.

Start Me Up

As soon as you reach the top of the stairs, get ready for some pain; there are some toxic headcrabs up here. These little guys are virulent, and will knock your health down to one point when they hit you. You’ll gradually recover your life over time, but it’s still pretty damn annoying, so be sure to let Alyx take them out before risking your life charging ahead.

Around the corner, you’ll come across your first antlion pit of the expansion pack. These pits will spawn infinite antlions if you can’t find some way to plug them up, but luckily for you, you can do exactly that by smacking a car into the pit so that it falls in. No antlions will be able to emerge thereafter. When the pit here is plugged, move over to the lever nearby and start churning away at it. More toxic headcrabs will come under it as it raises, so deal with them, then return to the lever and keep twisting until it’s all the way to the top and clicks into place.

Through the gate, you’ll find a couple of headcrabs and a long passageway filled with barnacles. Although the barnacles are in your way, they’ll act as a useful hedge against the zombines and zombies coming your way, so just light up the mobile enemies, then allow Alyx to finish off the barnacles. When you reach the small squad of zombines at the end of the hall, be sure to check the hole in the wall for a box of shotgun ammo.