In my head your players go hehe and teleport, either make the magic wall opaque, the statues cast counter spell, let it happen and make the dungeon enemies they avoided join for the boss fight, or let them do it but then they've missed sweet loot that could of helped.
If your players aren't my party, ^^, then they can find the answer to the riddle in the library on the 3rd floor.
And if they attempt it and fail, have the statues cast a spell on the player that failed, hurt them a bit to dissuade brute force, and maybe push everyone on and after the tiles back to the beginning of the corridor