When curious about what is behind a locked or closed door, use "The Eye" to see behind it. Get close enough that when you drop "The Eye", you do not pick it up when dropping, but it disappears. After that, look through "The Eye" and you should be able to see what is behind the door. This may require several attempts. Note: You may lose "The Eye" if you or the enemy destroys it. If that happens, you will be blinded for several seconds.