When helping in another player's Treasury, you can choose to perform a Heist. By doing this, you steal as many resources as your Noble can carry and have them run to your Keep to drop them off!
  • Drag & drop your Noble in the target's Treasury
  • Tap on your Noble
  • Tap "Heist"
If you are caught your rapport with the other family is reduced. If you are not caught they are informed someone heisted their treasury but they are not told who did it.