The story follows young Dorothy Dale and her friends as they confront a series of disappearances and criminal plots that unsettle their community. When a companion goes missing, Dorothy leads searches, traces clues across rail lines and into the mountains, survives capture and danger, and adopts a disguise to expose two scoundrels. Episodes include narrow escapes, a storm, and a squandered bullet before a surprising ally helps bring the mystery to light and safety is restored. The narrative emphasizes female resourcefulness, steadfast friendship, and persistent detective work within a brisk, adventure-oriented structure for younger readers.