Entering the cave, Cath'rinne can see the simple bed and camp of the monk, but presumably rushes past to explore the cave.
It is indeed very deep, and Cath'rinne soon gets out of the fading light of the setting sun. There is no way the monk is going to see her when he returns, not unless he has some superhuman senses, but then Cath'rinne does not see anything either. The smell and sounds are those of stale air and dripping water.