Part 6

Return to the main room and find a door with a headcrab behind it. Open it, immediately retreat, then carefully shoot the headcrab.

When you reach a ladder, equip your pistol and slowly climb. Shoot the top of the large explosive containers to destroy the zombie and headcrabs nearby. Quicksave before attempting this.

Alternatively, use a movable metal barrel near the entrance. Push it to the ladder area, against the opposite wall. Jump-crouch onto the barrel to easily shoot the explosives without taking damage. You must shoot the explosives twice for them to detonate. If you take too long, headcrabs may escape and attack a nearby scientist.

Proceed along the walkway past the ladder to a dead-end where a zombie is performing a ritual over a dead scientist. Look for a large explosive device; it may or may not be present if previously detonated by houndeyes.

If the explosive is absent, use your pistol to head-shot the zombie. If present, lure the zombie near the explosive, then retreat around the corner and shoot the explosive twice when the zombie approaches. Run backward immediately after firing to avoid damage.

Go back to the top of the ladder and turn left to find a scientist. Talk to him, and he will follow you back to the zombie area. He will use a retinal scanner to unlock a door, granting access to a room with a first aid station, hand grenades, and bullet clips.

Return to the houndeye room. In the short corridor ahead, push a movable barrel close to the door. Position yourself beside the barrel until you hear a teleporting sound, then get behind the barrel. After a vortigaunt breaks through, toss a grenade into its room. Enter the room to find more bullet clips. If a headcrab approaches as you exit, shoot it.

Past the D475-KL sign, a zombie will climb through a grating. Instead of fighting it, toss a grenade down the floor hole on your side of the bars to destroy a headcrab in the water below. Toss more grenades if needed.

Return to the room where you found grenades and resupply. Go back to the floor hole and drop down.

Explore the watery tunnel until you find a platform with a valve wheel. Use the wheel to flood the area, then swim to the nearest ceiling grate, which will open, allowing you to exit. You can ignore the nearby zombie.

Proceed down the hall to section c1a1c: CANAL AREA.

In the large room with a platform lift, collect two bullet clips near a dead security guard on the walkway.

Instead of using the lever to activate the platform lift, drop from the right side of the unmoving platform onto the sloped surface underneath. Hold the "Move right (strafe)" key to slide down onto a narrow ledge next to a first aid station without taking damage.

Jump across to the main floor using the raised cement structures. Quickly shoot the houndeye that teleports onto a large crate. After it falls, shoot it through a crack in the crate or bash the crate open with your crowbar. Bash all crates for more bullets.

Proceed down the adjoining corridor to a room with a metal walkway. Strafe left to avoid the bullsquid's toxic spit when it teleports in.

Move onto the remaining metal walkway, turn right, and jump to the lowest set of nearby pipes.