It's one of the best days at South School: Field Day! That means bean bag tosses, relay races, and tug of war. When Mr. Deltoid announces students will pair up to compete for a mystery prize, Harry and Doug are determined to win. But at what cost? Harry's sneaky tactics leave Sid and Mary grumbling. They even claim he's cheating. Harry insists he's playing fair and square. Doug doesn't know what to think! He must prove his best friend is innocent...