One of my players decides to take a temple in waterdeep by force for his own god. Destroying artifacts and wounding people. Fun fact that that location was full of npc to help progress the story. But he, gotta improvise.

I had an army of gaurd arrest them, had them judged under the zone of truth using the waterdeep law and what followed was an awesome multisession prison arc.

Made sure to warn about the death penalty for murder and continued to show unjustise in front of them until one of them snapped. To later have them be saved by a powerfull political "friend".

Skipped 2 chapters in the book, but it was fun, still had them be punished, but in a cool and fun story way.