Thirteen-year-old Lila lives in a room that is a portal to a thousand fictional worlds, but the real world of Oakhaven is becoming far more unsettling. When a "Spectral Mailman" begins delivering letters consisting of nothing but "Blank Pages," Lila realizes she is being summoned. As a descendant of the Evergreen Lineage, she possesses a dangerous level of empathy that makes her the perfect target for messages of "unfinished business." To stop the murmurs, Lila must uncover a secret that her family has been trying to deliver for generations.