When twelve-year-old Adeline Perle’s transient military family finally plants roots in an old, creaky mansion–Cannondale–the girl craves to build the lasting friendships that she, as a constant outsider, never had. On the cusp of bonding with an affable group of teens, Adeline discovers a secret door, unveiling portals to extraordinary realms where she is confronted with disappearing creatures and magical people, good and evil, and a boy who’s desperate to help her find her way home.