Half-Life 2 Walkthrough -> Through the Channels
Physics Challenge, Stormtrooper, and Cutters
The first "physics" puzzle awaits you. To escape the gloomy room, load the left side of the plank with bricks. The right side will rise, sending you straight into the arms of the Combine's bionic helicopter. I advise you to run quickly and, upon hearing the distinctive sound, seek cover.
Wooden crates and planks are poor, unusable cover. Slate and iron will provide good protection if you can crouch so that they are between you and the helicopter. Quickly run left around the corner. Check the next Lambda cache, smash the crate, and go into the water-filled grotto for a first aid kit.
Be very careful on the slippery ground. There are more lickers (suckers) here; use a crowbar or, if you're tired of it, throw any barrel and run under them. Repeat the same trick with another batch of hanging "tongues." In the boarded-up room, you'll be met by a local.
Help him get rid of a new enemy—three Cutters. Collect supplies in the room and move on. The Cutters are easily shot from behind the door with the stretched mesh. Around the corner, take out your pistol and light the barrel on fire, then retreat. At the exit from the catacombs, shoot the soldiers, then retreat through the door to slowly deal with a whole swarm of Cutters.
Behind the door opposite is a passage. Pay attention to the red lamp—it guards the passage to a secret storage room. Keep a crowbar at the ready; the ventilation shaft is inhabited. On the way back, take out your pistol and quickly blow up the barrel next to the passage from which you came.
Go down and lure the soldiers out. After that, calmly climb back up the stairs and shoot everyone as they appear. Now you have a submachine gun in your hands. Check the dark passage on the right for supplies and entertain the lone zombie.
A logic puzzle
Climb onto the mechanism and, seizing the right moment, quickly dive toward the hole in the wall on the left. If you make a mistake, you'll be crushed. Halfway there, catch your breath and dive again.
As you emerge from the water, prepare your machine gun: you'll face a battle with Unification soldiers and a pair of cutters. In the heat of battle, it's easy to miss the tongue of a remora. Climb onto the pipe and, avoiding the remoras and jets of steam, move toward the "lambda" and the boarded-up passage.
Lots of water and cutters
Once out of the water, quietly and carefully take out the soldier next to the car with your pistol. When the barrels roll toward you, don't hesitate—detonate them immediately. After a short but intense battle, dive back into the catacombs, into the friendly embrace of the cutters.
At the dead end, climb into the air duct and mentally prepare for a swim. After jumping into the dark warehouse with barrels, try to get into the water as quickly as possible – cutters are flying. When they emerge from another duct, carefully light the barrel and enjoy the fireworks. Shoot the surviving robots.
Stack the barrels and climb onto the catwalk. At the other end of the corridor, among the cluster of pipes, find the red handle and turn it. Climb the ladder back and return to the warehouse.
There, without waiting for the cutters to visit, jump into the water, dive into the pipe, and emerge on the other side. A new problem has arisen – how to get to the opposite side of the room. It's too high above the water. You'll have to dive. At the very bottom, several boxes and spools are blocked with boards. Free them and use the "floats." Escape into the light of day.
Radioactive Waters
A long corridor awaits you, battling soldiers and cutters. First, run right into a dead end and dispose of the robots. Afterwards, draw your submachine gun and give the soldiers on the other side of the corridor a warm welcome.
After passing two more cutters, gather supplies and cross the makeshift plank bridge to the rebel cache. Jump down. The Geiger counter has started to work—I strongly advise against stepping on those green, oily puddles. Those who want to can take the pipe to the ammunition stash on the right. The rest of you, move forward.
Help the rebel get rid of the headcrabs and grab ammo from the box with infinite ammo.
Your pistol will be your best friend for the rest of the level. The settlement is infested with headcrabs, which the Combine is shelling the area with. It's best to shoot these creatures from a distance, dodging their jumps.
A few times, the headcrabs will dig themselves out of the ground. The zombies lying down are actually just resting. Be careful—a zombie will probably throw a barrel at you. Carefully avoid the dangling live wire. Don't touch the walls of the sparking train car.
Just beyond it, next to the bridge, another victim of the headcrabs is lurking in the radioactive sludge. Run along the bridges to the "garage," where you'll be provided with an amphibious vehicle.
This original structure will become your "home" all the way to the "Eastern Rock."
Go ahead! Manually open the airlock (beware of the headcrab hiding between the boxes) and burst into the autumn dawn.
Source: gameslife.ru
Radioactive Waters: Half-Life 2 Walkthrough