One summer afternoon, Shawn goes for a drive with his parents and dog, Ace (Alf in the Japanese version), but the family car suffers a flat tire in front of an abandoned mansion. Ace is upset by something inside the mansion and leaps out of the car to investigate. Shawn's parents follow Ace, but fail to return. As Shawn tentatively approaches the dilapidated structure, the entrance door swings open, and he's drawn into a magical vortex. Reunited with Ace, Shawn must travel into the heart of the Deep Labyrinth to rescue his parents.