One summer afternoon, Shawn goes for a drive with his quarreling parents and his beloved dog, Ace...but the trip quickly turns sour when the family car suffers a flat tire in front of a seemingly abandoned mansion. Ace is clearly upset by something inside the mansion, and leaps out of the car to investigate. Shawn's parents follow Ace, but don't return. As Shawn tentatively approaches the dilapidated structure, the entrance door swings open, and he's drawn into a magical vortex. Now, with Ace at his side, Shawn must embark on the greatest adventure of his life...into the heart of the Deep Labyrinth.