Harobed Village was quiet and relatively peaceful. Now, as you enter the huge alien installation, you expect hordes of Skaarj; but that's not what you get... Terraniux is instead crawling with strange alien Mercenaries, a new and deadly foe.
Passing through the airlock-style entrance, you will be in a large underground cavern with an immensely tall lift shaft rising up inside the cliff. If you go to the right here you can collect an Eightball Gun and a can of 12 Eightballs; if you shoot the sludge barrel apart watch out for the dangerous balls of tarydium sludge that fly about the place. Now, head for the other end of the room.
At the far end of this area is a button, another sludge barrel and an ASMD Core. There's also a door in the shadows on the right, but it's locked. So, collect the core and press the button.
For a moment nothing will seem to happen but then you will see a box descending the lift shaft. I advise getting round behind the back of the lift at this point (you will have first strike at the enemy inside), because when it reaches the ground the sides slide down to reveal an alien Mercenary. Mercenaries, armed with machineguns, rocket launchers and blue invulnerability shields, are tough opponents so this may be a hard first battle.
The lift won't rise yet, so when the Mercenary is dead, head for the door in the shadows which is now unlocked. You will enter a corridor with some weird holographic beams crossing it inside. Go along the walkway through the beams and an alert siren will sound - the base is on to you now, but don't worry, it won't make a great deal of difference.
One short corridor later and you'll be in a room where two Mercenaries will spot you and start attacking. Kill the Mercenaries then read the control panel at the far end.
"Biowaste Flow Control: the Biowaste flow is constant. Monitor it for dangerous fluctuations in viscosity or pressure. The alarm still seems to have problems, in case of malfunction activate the two override controls."
Collect the Bandages here then press the two buttons on either side of the room. In doing so you can also grab an ASMD Core and two Flak Shells. Return to the panel:
"Lift activated. All personnel are reminded to complete assigned tasks."
So, return to the cave via the alarm scanner corridor. The alarm won't activate this time. Once in the cave, climb on to the lift and it will rise.
I suggest that you ride the lift such that you are facing the button when you climb on, because as you rise you will see two Health Packs on the first beam across to the wall ahead which you can drop off to collect. If you do so, wait for the lift to come down then ride it up again; the second big beam across, quite a lot higher up, contains a Super Health Pack... you can collect it, but it's a long way down... if you're good then once you have the pack you can use the cross-beams of the lift shaft to descend step by step to lessen the damage.
Anyway, ride the lift to the top and step off into a small room. Pass through doors and you will be in a loft overlooking some pools of green biowaste and some rooms with polished floors. A Mercenary attacks from the left; squish it with your Flak Cannon. In this loft you can get various goodies including a Health Pack, a can of 12 Eightballs, a box of 50 Bullets, a Flare, a Stinger and two clusters of 40 Tarydium Shards; collect what you need. As you plunder the loft, a Mercenary patrolling the polished area below on the right will probably see you and start shooting at you. I recommend the Eightball Gun here. Then, drop down into the polished area on the left - you can go via the biowaste, it's harmless. There is another Mercenary here who drops a Flashlight when he dies. Collect the two ASMD Cores from the corner nearest where you dropped in, then read the control panel in this room:
"Drainage Status: Biowaste flow is at nominal levels. All pumps operational. Section C is empty and available for any Biowaster overflow. Please be sure that the regular pipe maintenance is handled."
If you follow the curved walkway over Biowaste that leaves the room near the control panel, you will come to a central room guarded by a Mercenary. Kill the Mercenary then retrieve the Health Pack that he drops, then kill the Slith who will probably climb out of the Biowaste.
There is an opening on the left wall covered by a force field. Read the panel underneath for information:
"Control Room Status: Pressurised and locked. Do not access except in case of emergency situation."
When you're done in here, follow the next curved walkway round into the second polished-floor area. Collect the Toxin Suit and Health Pack here, then read the control panel.
"Security Status: Intruder detected at entrance. Activating security screens on Scientific Research Lab and Hydroponics Section. All security elements deploy around access points in Sections A, B and C to deny intruder access to Lift 1."
Well it's fairly clear where you will have to go when you get inside then... anyway, take the next door along from the curved walkway and into the next room. If it doesn't open, you haven't killed all the Mercenaries and Slith that have spotted you, so go back and weed 'em out.
Through the door you will be in a dead end with a control panel and a button. Read the panel.
"Pumping station has been activated. Expected storage capacity after operation: 32%."
All done here, so press the button to load up the next level.