It's the strangest list of components I've ever seen, but a lemon is the final thing we need.

Yes, a lemon. No, I'm not joking.

You won't find it in the lunch room, either.

Nowhere - you'll find lemon seeds in a very unlikely place, though: the bio lab.

Apparently the hellspawn in the cage poops out lemon seeds.

If we could kill the horrible creature, we'd have free access to the pile of lemon seeds in its cage.

Something strong enough to totally destroy it, whatever it is.

Try searching the labs yet again - and check out the computer to know your enemy better.

Go to the geology lab and grab the big flask - if Vinny doesn't want to, you'll need these hints.

The acid plan didn't quite work out, but the air freshener might be useful.

You can examine it in your inventory to find out what it's made of.

If you used the computer in the bio lab earlier, you were given a few bits of information that may now prove useful.

Hell mites get sleepy around potassium sulfide - and that's an ingredient of the air freshener.

Use it on the nearby air duct to put the creature to sleep.

Don't celebrate quite yet - even after grabbing the seed out of the cage, we still need to do some science before these seeds become a full-on lemon.