ToME: the Tales of Maj'Eyal

So I was over on the wiki reading about rogues before making a full on attempt at one and read this about the maze
"Rogues will discover a special scroll of lore which will teach them how to make a poison gas trap."
Well I've cleared the maze and ran through it twice, theres nothing there...

You must have some trap skill the first time you enter the maze to find the trap.
Or something like that, I'm too tired to check the code.

Any class that has at least one point in Trap Mastery will find the poison gas trap in the Maze.