In 1960s Toronto, two girls retreat to their attics to escape the loneliness and isolation of their lives. Polly lives in a house bursting at the seams with people, while Rose is often left alone by her busy parents. Polly is a down-to-earth dreamer with a wild imagination and an obsession with ghosts; Rose is a quiet, ethereal waif with a sharp tongue. Despite their differences, both girls spend their days feeling invisible and seek solace in books and the cozy confines of their respective attics. But soon they discover they aren’t alone–they’re actually neighbors, sharing a wall.