For higher level versions, I can imagine having fun with a dominate person trap. Lower levels might see similar things done with Charm Person traps- with casters a decent way down the hallway using Message to make suggestions like "stab the wizard" or "amazing how cold it is down here, why not warm all your friends up with a fireball at point-blank range."
Iron bars can be added as appropriate to block the advance of the party whilst letting through the message spells.
For a more comprehensive thrashing here, soften them up by spamming touch of idiocy spells by whatever means during the lead-up to this encounter.