This adventure is about Lilac and Penelope.
Many people in Adventure Bay say that an old treehouse is haunted by a ghost. Only Lilac and Penelope don't believe it's true, so they decide to investigate. Somehow, they meet a friendly ghost (different ghost) who sends them back in time to where a group of kids used the clubhouse as their club. Can Lilac and Penelope figure out how to get back and do something about the ghost?