Worlds Next Door - C E White - Bog

Twelve-year-old Janie Rutland somewhat grudgingly befriends Reggie Rankin-the weird new kid at school-and finally has someone to investigate her curious sightings in the abandoned house next door. When they find there's an impossible world in danger of total destruction, they face a choice. Do they have what it takes to save it? An eccentric fellowship gathers as they embark on a perilous quest in a race against time and their own fears. Traveling in what can only be described as a pirate hover ship, they're threatened by monsters and storms, shipwrecks and death. Can they find the answers they need to save Sian-and maybe all worlds?