Thak
I think Thak is maybe ok with trying to kill the Rat who would be King, she has her suspicions about him. She wouldn't bring it up, but she would follow along.
She has no interest in getting the Crown back for him, but we should be able to find the thieves without too much difficulty. We have a vague idea of where they are above ground, because I have the Dwarven underground abilities, and could judge rough distances to the dog from up top and then we should be able to search door to door within say a range of 100 yards of that area. We could ask people to let us take a look around. If they let us, which I would since we are 5 well armed people, we can assume that they aren't in on anything. We give them some copper ad wish them a nice day, maybe even tell them we are looking for some thieves who have caused some problems with some rats. People might have heard some shit. If they don't let us look around in the house, we would have to play it by ear. Maybe offer some coin. That would probably get us in the door to where the thieves are, just so they would try to take our stuff.
I think this plan is ok. If anyone wants to second it I'll implement. Please don't make it take till next monday for us to do something.