Eleven-year-old Allie Nichols is climbing in the steep and rocky Fossil Glen when she discovers she is in a dangerous predicament. A ghostly voice one that Allie feels she can trust guides her down the cliff face to safety. Soon, however, the ghost returns to ask Allie for help. Along with her friend Dub, she sets off on an adventure to discover who this ghost is and why it needs help. Little does Allie know the dangerous and mysterious world of ghosts and criminals she is entering! Follow Allie as she tries to balance crime-solving, friendships, and family life in this exciting novel.