It's Downtown Day in Elwood City, with all sorts of fun games and activities. Arthur, D.W., their parents, Baby Kate and Pal are all out enjoying the activities when suddenly Baby Kate starts crying. The noise seems to upset Pal and he ends up with D.W., then breaks away and runs off. As Arthur and his friends chase after the apparently lost dog, Pal seems to be on a mission the entire time. (thetvdb.com)