The party comes into town as part of a group of guards for a caravan. The mayor of the town upon seeing the group tells them of a demon that has taken the town's children, 130 in total, into forest and the mountains beyond. Only one child remains, who had a broken leg and couldn't keep up with the "demon" and fell behind and then came back to the village. The children were taken the previous day. The mayor offers a large sum of money for the children to be returned.
The "demon" is a human magician who the mayor had hired the previous year to cure a plague in the town. I modeled the plague on cholera and had the magician seal the old well, after adding an alchemical mixture, and have a new well constructed uphill and in a less densely populated area. The mayor withheld payment for some bogus reason. I used that the mayor didn't think moving a well was worth the sum he promised. The magician promised to return in 1 year and 1 day, and if not paid he will exact his payment. He returns and uses magic to take awa