Part 14

First things first, hop out of the water and move forward. You'll see three little Chumtoads that'll teleport away. Check around where the middle one was sitting to grab a couple of Snarks.

Quick-save here, then dive back into the water and follow the tunnel. It'll lead you to a deeper pool. As soon as you pop out of the tunnel, hold down the 'Swim up' key until you surface. Get back onto the path surrounding the pool. Look for a tunnel on the opposite side and head into it. Keep going until you see the 'ba_xen3' section load.

You'll come to some vines blocking your path; bash through them and drop down. Turn left and move forward into a big outdoor area. You'll see a series of floating platforms ahead – this is your first big jump challenge. Quick-save again, just in case! Start by jumping to the leftmost of the three closest rocky platforms, then to the next, and then the third.

These platforms move up and down, so time your jumps. Wait until a platform is at its highest point before leaping to the next. When you reach the sixth platform, get out your .357 Magnum and quick-save. Now, here's a tricky part: jump to the next platform, and as soon as you land, turn left and crouch-walk quickly to the edge. Turn left again to face the platform you just jumped from. You'll see a Vortigaunt teleport onto it.

As soon as it fully appears, it'll run to the left end of its platform and try to zap you. If you aim at the left end of the platform before it gets there, you should be able to take it out without getting hit. The other two Vortigaunts will appear a bit further away, so you can switch to your pistol and take your time dealing with them.

Once all three Vortigaunts are down, quick-save. Now, jump across the remaining platforms. When you reach the last one, leap to the big cave tunnel entrance. Get out your shotgun and move forward. You'll encounter some Houndeyes; stop and let them come to you so you can blast them easily. There are more outside, so clear them all out before entering the next big cave tunnel.

After exiting that tunnel, jump to the nearest floating rock, then to the second, and finally onto the big, donut-shaped rock. Turn left from here and face the small healing pool. You'll notice two more floating rock platforms beyond it. These lead to a secret side cave, but it's a really tough jump. The second platform gets destroyed shortly after you start trying to reach it.

Stand on the donut rock, facing the first platform past the healing pool, and quick-save. Run over to the small ledge just to the left of the healing pool. From there, jump to the left side of the first rocky platform. Immediately turn right, run to the edge of this platform, and jump to the second one. Seriously, this jump is brutal, and you'll probably fall a lot. As soon as you land on it, turn and jump to the cave entrance. Run inside quickly to avoid damage from the second platform's explosion.

Inside the cave, grab the ammo canister near the dead HEV suit. Head back to the cave entrance and look at the donut-shaped rock. Wait for an alien flyer to blow part of it up, then use your pistol to shoot down any Vortigaunts that teleport in. After they're dealt with, use the teleporter orb in the cave to return to the small healing pool. Crouch-walk out of the pool onto the ledge next to it, then jump across the smaller gap to reach the main part of the damaged donut rock.

Go to where a large rocky spire has fallen over. Crouch-jump onto its base, then onto its main body. Follow it along the ground until you reach the other end. Go around behind some big rocks to find vines covering a hole in the ground. Crouch-walk onto the vines and bash them to fall into section 'ba_xen4'.

Grab your pistol. Follow the tunnel, keeping your head above water as much as possible. When you go underwater and reach the bottom of a vertical shaft, mash the 'Swim up' key to surface quickly. A Bullsquid will spot you! Move so the nearby rock and crystal are between you and it.

Watch the Bullsquid's movements. You might need to adjust your position too. Once you're in a spot where you can see it while bobbing on the water's surface without it spitting at you, shoot it with your pistol until it's dead. Alternatively, you can hop out of the water, crouch behind the rock, and slowly strafe left until you can get some sneak-shots on it. Then, jump out of the water and drop into the large stream that leads to a waterfall.

Quicksave! Go to the edge of the waterfall and look down without falling. Use your .357 Magnum to take out the Bullsquid on the small island below, strafing to dodge its spit. Once it's dead, go over the waterfall, making sure to land in the water. Get onto the Bullsquid's island and scan the back wall for another waterfall – that's your next goal.

You'll use the big, round 'whoosh-thing' on the island to get up there. Stand on the side of the 'whoosh-thing' directly opposite the waterfall, then look up at the top of the waterfall. Run onto the 'whoosh-thing' and jump, then hold the 'Move forward' key until you land. If you fall back into the water, just try again.

Head down the tunnel past the waterfall, whacking any Barnacles you encounter. You'll reach a healing pool with a dead HEV suit and an ammo canister. Grab the canister, then take the tunnel to the left of the healing pool. As you near the end, get out your pistol and quick-save.

Turn on your flashlight and slowly crouch-walk up to the end of the tunnel, staying along the left edge. If you're careful, you'll be able to sneak-attack the Bullsquid waiting there.