Part 17

Past the explosive containers and a dead bullsquid, wait for three houndeyes to appear and eliminate them with the shotgun or crowbar.

Enter section c1a4f: RESTORING MAIN POWER. In a large room with hanging cables and barnacle tongues, deal with a bullsquid chewing on a dead scientist by lobbing a grenade and then firing your assault rifle. Alternatively, leave it alone.

Locate a first aid station in the room's opposite corner.

Get onto the narrow platform extending from the main floor. Crouch-jump onto its right-hand railing, then jump to a visible ladder.

At the bottom of the ladder, carefully walk or crouch-strafe onto the short pipe underneath. If unsuccessful, hit the "Jump" key to let go of the ladder (quicksave first).

Jump from the pipe onto the nearby flooring.

A first aid station is near a standing scientist. Further on, a large pipe leaks toxic goo. To pass safely, take a running jump-crouch onto the pipe, walk along it, and drop to the floor past the spill.

Double-barrel a zombie in the head, then move past it to find a small movable platform. (Optional: Lure the zombie into the toxic goo to kill it.)

Get on the platform, press its button, and crouch to avoid the bullsquid's spit from below.

Climb the ladder next to where the platform stopped, then drop onto a walkway on either side.

Move along the wall, keeping an eye on a constantly moving platform, until you reach another ladder.

After the fast platform passes, quickly move to the ladder and climb it. At the top, walk or jump onto the large slanty thing and press the red button at its top.

Jump onto the reactor top where a scientist is located. Move across to another slanty thing with a button at its top, press it, then run down to a ladder.

Climb partway down the ladder and watch for the fast platform. Move to the bottom and get against a wall when it's safe.

Carefully make your way along the walkway back to the top of the ladder leading to the movable platform.

Climb down to the platform (or drop to it) and use its controls to return to the area near the toxic spill.

Cross the pipe again to avoid the spill, and use the first aid station if needed.

Drop back onto the pipe segment next to the big ladder and climb to its top.

Turn on your flashlight and slowly climb down the ladder, looking for a small ridge on the large pillar to the right. Crouch-strafe onto the ridge and walk along it to a point where you can drop to the floor safely.

Push/pull a small metal box near the first aid station through a doorway and place it next to a large metal box. Jump onto the small box, then crouch-jump onto the large box.

Crouch-jump onto the thick metal cable running along the wall, follow it, and drop to the floor past the electrified water spill. Move on until you return to section c1a4b.

Section c1a4b (fifth time): RETURNING TO THE FIRING CHAMBER. Move back to the bridge with explosives, recross it, and use the switch in the door-switch room to return to section c1a4i.

Section c1a4i (yet again): BLAST THOSE TENTACLES! You have two large walkway gaps to jump (quicksave before each).

When you reach the boarded-over doorway, break the boards with the crowbar and wait for the tentacles to calm down.

Climb back up to the top level of the firing chamber. Quicksave frequently and quickrestore when taking damage.

Climb the first ladder on the left as you enter the firing chamber. Quickly climb it, then move away or toss a grenade to avoid tentacle attacks. Repeat this process for the next two ladders.

Resupply on grenades in the room past the firing chamber's upper platform.

Return to the control room, watching out for a new floor gap. This is your last chance to visit the barnacle-related secret area if you haven't already.