Having defeated the Garr, a vicious tree monster who lived within the enchanted woods of Watch Hollow, Lucy and Oliver Tinker now have the home they've always dreamed of: Blackford House. Powered by a magical clock and full of curious rooms and improbable knickknacks, Blackford House brims with the promise of new adventures. Yet when a strange governess arrives from England--bringing with her the Kojima twins, Agatha and Algernon--the Tinker children's once bright future quickly begins to dim. The Kojimas claim to be the rightful heirs to Blackford House, and soon after their arrival, a great evil enters the Tinkers' new home, cursing it and turning it into an ever-changing labyrinth. As a result, Lucy and Oliver, along with their clock animal friends, must now join forces with the twins to escape this labyrinth and save Blackford House, all while a new monster lurks around the corner.