All Sam Swallow wants is to join the Little League baseball team. But on the way to the park he stumbles, hits his head and falls into Riddleworld, a land where birds talk in puzzles and cats wait to pounce. Nothing is what it seems to be in Riddleworld. Sam himself has been transformed into a bird. To get back to this world, Sam needs to solve some difficult puzzles, make a few unlikely friends and avoid the cats at all costs.