The Drunken Lizard Pub

Well, thank you for your answers. I have now the possibility to reach the next part of the level. Unfortunaly, in this darkness, I don't find the lever linked with the door. I'm affraid I have to leveling to upgrade my cartography skills. How many points do you recommand (my cartography is at 5) ?

How do I reach the third level ?

I've completed the entire level but I don't find any stairs leading to the third level. I reach a control panel that requires 8 candecium dusts and a bit farther, a dead end with 2 wooden Barrels and 3 torches on the walls. Obviously I've put the dusts on the ...