Need just a little help progressing

I've been following the degrasi bases, and I've ended up at the one in a deep jellyshroom cave filled to the brim with giant snake-eel murder things. From the information I've gathered, it appears the survivors moved into a base deeper in the cave, but I've explored every inch of it and found nothing such. The deepest part of the cave, a narrow trench, has a pathway that requires a thermal suit. I thought this was my ticket, but upon further investigation, it's just a shortcut to another part of the cave. Where else am I supposed to look?

If this is truly the end of the trail, you can go ahead and tell me, otherwise try to give me a subtle hint in the right direction. Something like, "It's not in the cave" or "Try looking for blah blah blah"

Thanks a lot.