Part 25

Climb the stairs to reach a ledge and collect ammo. To exit the ledge, hop onto the railing next to the stairs, run forward, and drop safely past the electrified rail.

Move towards the large doorway leading to the next area. Retreat to the corner left of the doorway upon hearing vortigaunts (creatures that can teleport) teleporting in.

Keep your shotgun ready for any vorts or marines that appear, but remain in the corner until the fighting stops.

Proceed through the doorway and eliminate any survivors with your assault rifle. Be aware that one vortigaunt hides in a dark niche on the left side of the area.

Equip your crowbar and break the boards off the doorway on the left. Enter the room and ready your shotgun.

Position yourself next to the security guard until a vortigaunt teleports just outside the doorway, then quickly defeat it with a double-barrel shotgun blast to ensure the guard's survival.

Bash the boxes in the room to find .357 ammo and health.

Entice the guard to follow you into the room across the hallway.

Run towards the wooden boxes in this room to cause the ceiling to partially collapse, dropping headcrabs (or shoot the ceiling with your pistol from a distance).

Quickly retreat while your guard deals with the headcrabs.

After the headcrabs are dead, go to the spot next to the first aid station behind the wooden boxes. Turn around and toss a hand grenade into the ceiling area to eliminate the last two headcrabs.

To reach the ceiling ledge, jump-crouch onto the single box, then jump-crouch onto the two-box stack, and finally jump onto the ceiling ledge.

Check the back of the ceiling area for three armor batteries, then drop back to the floor.

Break the boxes to find another armor battery. Use the first aid station if needed.

Whack the guard for his pistol. Quicksave (save your game quickly) before proceeding to the other end of the area where a marine mans a large, sandbag-protected gun.

Option 1 (Direct Approach): Run to the right and stand behind the large wooden crate until the gun stops firing. Bash the crate with your crowbar, then immediately run forward and jump over the track. You may get shot, but you can then move next to the sandbag pile and jump to see and shoot the marine manning the gun.

Option 2 (Grenade Approach): Get behind the large wooden crate on the left. Crouch-strafe slowly to the right until you can see the right edge of the gun. Toss a hand grenade or AR grenade through the gap to the right of the gun to blow up the marine. Quicksave before tossing the grenade to avoid using multiple.

After the gun is disabled, jump to its side of the track if you are not already there. Jump onto the sloped cement beam that leads to a horizontal crossbeam.

Jump-crouch onto the crossbeam, then jump to a narrow ledge. From the ledge, jump onto a beam with an armor battery.

Carefully slide down the sloped beam on either side. Move along the ledge next to the track until you can press against the large red "BLAST DANGER" doors.

After the doors open, back up to a safe distance. Use your pistol to detonate one of the tripmines just past the doors, or carefully crouch-walk under them.

Past the doorway, crouch-walk slowly towards the top of the ladder. Look down at the walkway below for a marine. If careful, you can sneak-shoot him with the .357 before he spots you.

Climb down the ladder and go through the doors near the marine to find another rail car.

Search the room to the right before getting on the rail car to find a health pack and .357 ammo in a wooden crate.

Check the area just past this room for a hidden HEV station (a health and suit charging station) in an easily missed wall niche.

Get on the rail car and ride it forward slowly, crouched and pressed against the control console.

When between the two red laser alarm beams, stop the car and stand up briefly to locate a bullsquid ahead.

Use shoot-and-duck tactics to kill the bullsquid with the .357.

Slowly move to the right on the car to sneak-shoot a bullsquid on the walkway to the left.

After the second bullsquid is dead, crouch-ride the rail car until it is next to steps on the right.

Get off the car but do not go up the steps. To avoid activating the turret, jump onto the railing to the left of the steps and crouch-walk along it until well past the turret.

Collect the AR grenades from near the dead bullsquid.

Use the rail-walking trick to get back past the turret and onto the rail car.

Ride the rail car forward until you reach a ledge on the left with a turret and a door. Stop the car and open the door.

Be ready to shoot the bullsquid past the door with a .357 slug and strafe left to avoid its toxic spit.

After the bullsquid is dead, move slowly into its room. Use your pistol to sneak-shoot a headcrab hiding around a corner on the right. (There's a chance another headcrab is past the door on the left, but the bullsquid usually kills it).

Go to the back right corner of the room and use your crowbar to kill the barnacle (a hanging creature that grabs prey).

Look around for supplies before returning to the rail car.

Ride the rail car onward to where section c2a2e loads.