Unfortunately, the lift will be attacked by the monster you've already had the pleasure to meet. This time, you will lose another team member and you yourself will fall to the lower level. Go straight ahead to reach the climbing mechanism - as soon as you approach it, the creature will come up.
Instead of wasting your ammo on the creature, do not shoot at its tentacles, but run around it until you reach the harpoon-activating generator. Use kinesis to set it into motion. Try and keep your eye on the monster, at the same time, that will surely be coming your way. It's definitely a good idea to use stasis to slow it down, which will buy you some time to activate the mechanism.
After you activate the system, you should notice blue laser beams - you now need to lure the monster into the area operated by those beams. To drive the monster mad, destroy the three tentacles projecting from its head- this will prove effective at encouraging the monster to charge at you.
As soon as the monster is captured, run towards the small controls to the right, to initiate tearing the it apart, by. If you aren't quick enough, the creature will liberate itself, and you will have to lure it within the reach of the laser beams again.
When you manage to put an end to the creepy-crawly's life, collect the supplies it left behind and make your way to the climbing mechanism. The last journey up is devoid of any unpleasant surprises - when you finally reach the top, you will meet up with Ellie.