OOC:
OK I will push the story forward, we have either some misunderstanding I believe.
Mal, seeing that Thorem is no wiling to put his foot into the water moves south there Thorem were and steps we steps into the water and see that there is water tunnel en to the right of him that ends with what he believe is a up stairs (although it is on edge of his dark vision some dim light is coming tom upstairs and let him clearly see the stairs).
He see another hall to the left of him that seems more like a natural cave not a hall like anything you have seen before. He can't see the war end of that hall
OOC:
I reveal the right part of the map more than you should have seen, but there is nothing interesting to see and there is no way up - the tunnel you see int he map is just because this is ready map and I am to good at fixing pictures
Later you all return the first hallway and see the pillar lights go off, but the red light and sound of chest stay.