Half-Life 2 Walkthrough -> Through the Channels
Cries for Help
Heal yourself at the wall-mounted first aid kit. Ready for some fun? Jump out into the hallway and quickly knock out two Combines with a crowbar. The first target should be the soldier with the Glock 18 (too bad you can't fire bursts with it). Now you have a weapon. Leave the beaten civilians and, after breaking down the boards, move on through the level.
The first "real" Combine massacre
Kill the next soldier with the same pistol, aiming for the head. Missing shots or shooting at the body will quickly run out of ammo, but this way you'll have plenty. After that, head outside. Go down the stairs behind the fence (don't stop completely on the first landing).
A train will be arriving soon. As soon as it's within jumping distance, jump onto the roof and cross to the other side. Turn around and shoot the barrel, blowing up two soldiers. Quickly grab your crowbar, climb the stairs, and knock out the boards in the doorway.
Grab the first aid kit and ammo, and blow up the two barrels from a distance. Jump outside, smash your first ammo crate with the crowbar. Grab your pistol and blow up the barrels above the door. After that, you can slowly go around the corner and carefully shoot the soldiers on the opposite side of the "street." Climb over the fence and dive into the narrow opening, using the crowbar to clear a path.
Tip: Notice the "Lambada" scratched on the wall and memorize its appearance. This symbol indicates that rebels are storing ammunition and equipment somewhere nearby. After this, you have two options for passing this dangerous section: methodically shoot the soldiers or go all-out. Jump onto the rails, detonate the barrel near the turn, bounce off another barrel, and quickly eliminate the soldier.
Run down the corridor with the crowbar at the ready and take out another soldier on the stairs. Still holding the crowbar, cross the narrow bridge, smash the crates blocking your way, and carefully shoot the two soldiers entrenched below on the rails with your pistol.
After that, it's worth healing up and grabbing the "batteries" in the alcove on the right, then, running to the canal, jump into the water. That's it, this fight is over. It wasn't all that difficult.
Rebel and Vortigaunt
Swim to the red container, climb the ladder on the left to the roof, and jump into the hatch:
The train car's occupant will show you the way, and the Vortigaunt (a large, humanoid monster with a single red eye) will recharge your suit. In the first part, upon leaving the lab, they were enemies, and very powerful ones at that, but in the second part, they're best friends:
After a short but intense fight with two pieces of wood, you'll encounter a remora for the first time. While it's eating a crow, approach its tongue. When it drags you toward it, draw your crowbar, point it at it, and keep hitting it (the exact moment is easy to predict, but it's best not to risk it). Don't kill it with a pistol under any circumstances—it'll use up a lot of ammo, and with a crowbar, it only takes one hit. Hear gunfire? Ready your pistol and follow the sound.
A difficult firefight
Don't go out into the open. Instead, hide behind a large piece of concrete and eliminate two Unification soldiers. Now, be careful: there's a machine gun around the corner to the right. You need to sneak up to the corner past the barred "window" (be careful, there might be a soldier there), quickly pass the dangerous area, and duck into the pipe in front of the pile of boxes against the wall.
Keep your pistol and flashlight ready—you'll have to deal with a soldier in the pipe or the hiding place. Collect supplies from the hiding place, reload, and quickly get out.
Destroy the barrel, blowing up the (almost) defenseless riflemen, and then take control of the machine gun. Ammo is endless. It'll be fun: the key is to time your energy spit attacks on the soldiers and scanners. Be sure to detonate the barrel near the wall on the right—it's on a platform blocking the passage along the wall.
In any case, as soon as the barrels fall and the blue-black sides of the armored vehicle become visible, abandon the machine gun without regret and run along the narrow ledge on the right toward the pile of cars. There's a "Lambada" sign near the wall—first aid kits are lying to the left behind the car. Conserve ammo—use a crowbar against the clinging creature. Follow the advice of the lady hiding in the pipe, use the sewer. Use the pipe to get to the small square room (two Defenders are alarmed above), and then to the next one, filled with water.
Explosive barrels will start raining down from above. As soon as the burning barrel falls, immediately hold your breath and hide on the bottom to the left of the entrance. Once the explosions subside, kill both Combines, collect the loot scattered across the water, and proceed through the passage courtesy of the explosion.
Barrel Hell
At the exit, you'll encounter several Combines in an open area. Don't conserve your ammo—it's scattered in abundance. Use the cover to kill the first two soldiers. Hide next to the ammo box and detonate the barrel just in time to get rid of the third. When four more soldiers run out onto the bridge, pay attention to the barrels under its supports.
Lots of Barnacles
After a short fight with two soldiers (you can use the bridge supports for cover), enter the narrow gap in the pipe to the right. Be careful—the ground is slippery and there are a lot of Barnacles, but they're easy to kill. Treat the next large group of Barnacles with a flammable barrel. While they're passing it around, light the barrel and enjoy the fireworks.
Make sure your health is at maximum. Don't jump into the water too quickly—let the burning barrel pass first. Several more will follow—hide behind the plank and don't forget to catch your breath. Carefully eliminate the Combine at the bridge.
Climb onto the platform, then use the ladder to cross the fence. Dive under the wooden structures and swim underwater to the end of the canal. After that, carefully use the barrels on the bridge to get rid of the Combine soldiers and, avoiding the falling "bombs," reach the next pipe.
Source: gameslife.ru
Through the Canals (Part 2): Half-Life 2 Walkthrough