Outside was chillier than before. Or was it just my body shutting down?

I wrapped my hands around myself, inhaling in and out softly, needing to tell my body that I was here, in charge, but my legs felt heavy and about to give out. One more step. I chanted with each step I took, until I was out of the library vicinity.

I stopped, rested on a tree, and looked at the cave. What do I do about the illusion? Not that I expected the strange witch to be waiting for me, but I kind of thought she would be hovering somewhere, or maybe had put a spell for...