Dargon

Oh my gosh, the switch blended into the wall pattern so well : / Thanks so much!

So I returned a necklace to Pathass in Gnass, and he said that one of my rewards is access to a spell tome. I ask him, "Have you decided what you would like to teach me?" to which he responds, "Read my book, not the one in this chamber. The hidden one. It will open to you now." I'm not sure that that could get anymore cryptic... I've been running around Gnass like a madman and I can't find any spell tomes, hidden or otherwise. Does anyone know where I can find the tome he's talking about?