Once the shipment arrives at the kingdom it seems that all the boxes are empty and for some reason most of the coins were replaced with small rocks and acorns.
"The gods have chosen to smite us today my brethren...but we must fight back"
"How damn it we're just men...insects before their power"
"We will have to find the dagger"
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.