After 12-year-old Erin moves to the small town of Pemblebrook, she is haunted by the ghost of a girl.At first, Erin is optimistic about her family's move from Chicago. It means more space away from her 5-year-old sister, Becca, and breathing room, unlike the cramped city-she's always loved the freedom of being in nature during visits to her aunt in rural Illinois. After discovering an old treehouse on the property, Erin encounters a ghost inhabiting it, a pale girl with curly blond hair dressed in old-fashioned clothing who seems to have the power to enter and take over her mind. Duga teases readers with a prologue that hints at who the ghost might be. There are plenty of classic paranormal motifs: the ghost appearing in the mirror, unfinished business, mysterious noises in the night, and possession. For those new to the genre, these tools are effective at creating safe, eerie spooks. Unfortunately, Duga's writing style is heavily expository: For example, the sibling relationship between Becca and Erin wears on the older sister, but this is largely stated rather than shown through their interactions. All main characters are presumed White except for Erin's new neighborhood friend, Tara, who is Black. This book works as a not-so-scary intro to ghost stories for young readers, but it might feel unsurprising for well-read fans of horror.A paranormal tale offering mild chills just right for younger audiences. (Horror. 8-12)