The door marked "UNDROS".

Cersi cautiously opens the door marked "UNDROS" and steps through into a room made of the same stone as the previous room, but much larger.

In the center of the room is a pool of shimmering blue water. It looks pure and delicious, and Cersi feels pangs of thirst. But this is a dangerous place, and she wonders if the water might be some sort of trap. To her left is a door labeled "EXVOS". And on the far side of the water is a door marked "DZOJA".