in the forbidden hall, there is a chest sitting in the middle of a room that looks like it has to be dispelled. there are multiple keystone braziers around it. when interacting with the chest, it implies that a certain combination of those keystones lit will open the chest. what is is combination?
i managed to figure it out while high as hell without reading the instructions the guards have until afterward. you should be able to do it. --- PSN: PowerBeard Don't give up, Don't give in... Without a beard you will never win.