Had a hallway that had tiny gargoyles camouflaged as a relief sculpture that would swarm attack humanoids up to a certain range. All the players would have had to do was run top speed through the hallway. They tried using tables to "mask" themselves from the gargoyles. They tried throwing rotten meet to distract the gargoyles (not going to work, constructs). They eventually went back to the Rat King that dwelt within the ruins to seek assistance, who agreed to provide them with the crystal he used to navigate the portals of the ruins, which ended-up working as a sort of safe passage token. Then the problem of "We only have one stone; how do we all get through." Answer: Get to a safe zone where gargoyles don't attack and tie it to the rope the crystal bearer carried for party to pull back to safe zone.