The Ghost, the Buttons, and the Magic of Halloween: Steampunk Sorcery, Book 6 (Unabridged‪)‬

Everyone in New Orleans thinks the Button family lives in a spooky old haunted house - except the three Button children. The bumps in the night are perfectly normal to them until one day when an elderly ghost appears to investigate this mystery with his mechanically enchanted umbrella. Soon he discovers a world behind their walls, a world that takes him and the three Button children down to a village far below their home, a village of jack-o-lantern houses, a village of scary creatures, a village called Halloween Hollow, where the streets are filled with magic and madness, especially Trick-or-Treat Street. Yet the hollow is being threatened by a monster called The Darkness. Now it is up to the ghost and the Button children to stop the monster and save Halloween.