Cassidy “Cass” Blake is the 12-year-old protagonist of the novel and the first-person narrator of her own story. Cassidy never feels like she fits in at school. She explains she is not like the pretty, popular girls: “[…] I’m all elbows and knees, round cheeks, and curly brown hair. I don’t even own nail polish” (2). Moreover, Cassidy feels like she does not belong anywhere in this world since her near-drowning experience one year ago. She doesn’t long for popularity, viewing it as utterly exhausting, but she has no close human friends.

Now imbued with the ability to pass back and forth between the Veil that separates the living and the dead, Cassidy feels more lost than ever. She is uncertain of the reason for her supernatural ability and doesn’t know how to help the ghosts she finds in limbo. Compelled by curiosity, she answers the tug of the Veil without any sense of what she should be doing once she gets there. As a result, she leaves feeling empty and sad. When Cassidy’s ghost-obsessed parents announce the family will be traveling to Edinburgh, Scotland, for summer break to scope out its storied, haunted past, Cassidy experiences the spirit world in a new and frightening way as she learns not all ghosts are harmless.