The First Riddle Door

The two humans and Mornenion arrived at a door. The door was locked and wouldn't open, no matter how hard Caithryth pushed it. So, they decided to see if Mornenion could climb the wall, but he wasn't able to get a grip to climb up. They then decided to see if all three of them could open the door, but when they did, they heard a clicking and shortly after two bolts shot from the door at them - some sort of mechanism to keep people out. Then, Mornenion saw the inscription above the door - it was a riddle. After some thought, Arthasdir suggesting that they holding their swords up in the air to solve the riddle, Mornenion decided to climb a pillar and when he got to the top, there was a click and the pillar fell down. The door didn't open though, so Mornenion decided to climb the other intact pillar, which, as he's thought, clicked and opened the door. They moved on, where they found a digsite.