DS version: Stuck on level 10 (I think, not sure of the level), in the sewer when the chalice/woman is following you through it. there are like 2 bridges, and then 2 guards, and 3 buttons in the floor you can step on and they turn yellow. (You can also see a gate that doesn't open.) I have no idea what to do. Seems unsolvable - a glitch in the game or my ineptitude? Help!