Casts "Waking Dream" -- if your puller is affected by this charm, they will auto-aggro and attack the closest PC.
Fun thing to do when this happens is to hit the charmed player once so that the NPC that cast the charm aggros, then train into the ballroom running circles. Lots of charmers in there so the other toon gets charmed and NPCs hit that toon. I think at that time NPCs start attacking each other shortly before the zone crashes.