I'm fairly sure you're in the wrong place, not quite sure which temple you are at, theres several, I'm assuming Fincher told you to go help bandits he sent off to the eastern temple? or did the don say there was one over there, if not speak to Fincher, should give you an idea on the map where it is, on the map its not terribly clear, but you need to approach the mountains shown on the map from the west side, so instead of going in the tunnel through the mountain, you want to head through a small passage north of where the tunnel is. if that makes sense. I have 4 discs, one with the don I'm just about to get, and didn't have to get through a blue barrier. I'm also trying to find a way through the barier, probably more scrolls later in the game.