Nancy Drew, a resourceful and independent teenage detective, relocates to the small town of River Heights. Eager for adventure and to establish her place in the unfamiliar community, she quickly finds a mystery to solve when locals report eerie occurrences in the dilapidated Twin Elms mansion. Determined to uncover the truth, Nancy pursues clues that suggest the mansion is haunted. She teams up with friends George and Bess to investigate strange noises, moving objects, and other inexplicable events disturbing the elderly Flora, who resides there. Flora’s claims of ghostly activity are mostly dismissed by authorities, leaving Nancy and her friends to dig deeper into the mystery.

As Nancy delves further into the case, she encounters various town figures, each with their own secrets and motives. Her investigation leads her to discover hidden passages and secrets within Twin Elms, deepening the intrigue surrounding the mansion's history. Along the way, Nancy faces several obstacles, including resisting forces determined to thwart her efforts. With courage and ingenuity, she pieces together fragments of the hidden past, driven by her determination to bring clarity and resolve to Flora's unsettling experiences. The story unfolds as Nancy navigates through deception and danger, leaving her to confront an unexpected twist that challenges her detective skills like never before.