Smurfs #19: The Jewel Smurfer, The

On the road leading to the town of Abelagot, two humans, Adhemar and Godillot discover an unconscious Jokey Smurf and take him along with them. After arriving in town, they meet a stranger who proposes to them to get rich by means of Jokey Smurf through slipping him into houses by night and forcing him to bring back the rich inhabitants' jewels. Available in softcover and hardcover editions.