"Greetings travellers! You must have had a harsh journey through the desert."
"We didn't see this city was on the map."
"We're just a few like-minded folks trying to keep the world out."
"How many people live here?"
"Just a few of us, and now you."
The PCs accidently start a fire and are caught by the local law enforcement. Since it was accidental, the punishment for the PCs is to fight the fire. Providing they can put it out before it burns down the town, they will not face any further punishment.