Although this is not represented in the storyboard, it will be interesting to put mirrors in less obvious places then on the walls. This is a concept that uses the shelves already in the room. All books are glued in place except for one, which can move outwards a certain distance, revealing a mirror on one side that can be used to bounce the laser.
A bar or rope is attached to the book and behind the wall a motor can pull the book back into place after a group of explorers have finished the room. Allowing the room to be reset easily.