Mikey finds himself in a strange and unfamiliar place after a magical ride off the rocket ship slide at the park. He soon starts to explore and meets a boy from this underground world, and they become friends. The boys spend the day playing and exploring before Mikey returns home back above the ground. Mikey awakes the next morning, thinking that he is remembering a dream but soon realizes that he is not dreaming, and he makes plans to return to...