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 abandonded 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 a worried 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 dark heart of the Deep Labyrinth.