Part 5

When facing the headcrab, you can either dodge its leap or let it see you, then crouch and back up around the pillar. When it walks into view, quickly move forward and crowbar-whack it to death. The headcrab may have its back turned, allowing you to sneak up on it.

Move on until section c1a0c loads. Time your run through the control room, waiting for the surge to hit the farthest spot, then quickly run through. Go back to the test chamber door and crowbar-whack the revived security guard to death to take his pistol.

Go back to where you picked up the crowbar. Crouch down and use it to bash out one of the doors' lower glass panels to crouch-walk through. Do the same with the next set of doors and watch the elevator crash. Turn right and climb down the ladder to grab an armor battery from the floor next to the elevator wreck. Climb back up and then up the ladder to the next floor.

Quickly get off the ladder and run through the doorway to find a zombie closing in on a security guard. Use the pistol to quickly head-shot the zombie before it kills the guard. If the zombie notices you, back away while the guard shoots it.

Hopefully, the guard will shoot down the other nearby zombie. Stay out of the way and watch. Talk to the guard to get him to follow you, then go through the open doors to reach section c1a1a.

Past the next set of doors, get your guard pal to notice two zombies ahead, then stay out of the way while he shoots them. Ignore or crowbar the dead scientist with a headcrab on its head.

At the path split, go straight to find the break room and employee locker room. Vandalize the soda machines with your crowbar. In the locker room, get two armor batteries from the "Freeman" locker and two bullet clips from the "Guthrie" locker.

Go back, turn left, and go up the slanty floor to reach section c1a1f.

Turn left and follow the hall back to the room you first entered. Notice the explosion that destroys a vent covering. Shut off the alarm using the security desk button, then go to the wall hole where the vent was.

If you can get the headcrab's attention past the wall hole, back off so your guard pal will shoot it. Otherwise, crouch-walk toward the crab until it's crushed by a falling computer bank. Stand up and look left to see a second headcrab. Shoot it or lure it to your guard pal. Crowbar-whack your guard pal to get his pistol.

Before reentering the computer room, go to the big doors leading to the tram arrival platform. Partly open them by crowbar-bashing the largest of the three panels on the wall to the right. Crouch-walk under the upper door, then run to the other set of doors and do the same. Grab a bullet clip from near a dead guard. Kill a scientist by walking onto his unsteady walkway and quickly retreating before it collapses.

Go back through the two half-open door sets and crouch-walk through the wall hole to get back into the computer room. Go to the back left corner and jump onto the slanty computer bank (use a jump-crouch), then crouch-walk through the crawlspace to drop into a corridor. Watch the scientist get headcrabbed and avoid the fallen vent shaft to the left of that room's windows.

In the dark room across the hall, whack a chair zombie to death and smash things. Past that, you'll reach an area where a security guard and a zombie are about to die. Grab the guard's gun and crouch-walk through the left part of the first set of doors to reach section c1a1b. You may need to crouch-jump to get through the doors.

Use the button panel on the left to make one of the doors open and close. Time your way through it. Turn right past the door and move forward with the crowbar ready. When a houndeye teleports in, back up, then charge and whack it as soon as it starts whining up a sonic charge. Do the same to the other houndeye attacking a scientist.

Move on to the next area with two more houndeyes. Crowbar them to death or use the pistol. If you jump into the side room one of the houndeyes broke out of, you'll find a first aid station.