As soon as dawn hit, Jack started running faster than he's ever run here. I was only just able to keep up with him. He didn't stop for almost an hour. As we ran I caught a few glimpses of terrain features around us; the trees appeared to be growing denser, and I could have sworn I saw either the same door we had previously found or another one like it.
We've found a new cave, but we've decided to move caves more often now; the creature appears to be better at finding us than we thought.
As for those messages, still not sure what to make of them. "return to the agent"? I'm going to keep digging through this phone to see if I can find anything to make better sense of it.