Nancy Drew and her friend Helen are visiting Lilac Inn, recently renovated for Nancy’s friend, Emily Willoughby’s, wedding. Nancy discovers that an impersonator is forging her signature to rack up bills back in River Heights. Emily tells her that there have been sightings of apparitions in the lilac grove. Stood up for a scuba date with Emily’s best man, Nancy is attacked while solo diving. Emily's inheritance is stolen during a blackout. Nancy experiences an explosion and cabin fire, an attack by the ghostly woman in the grove, and repeated negative interactions with inn staffer Maude Potter. Nancy impersonates the apparition only to come face to face with it, who looks just like Nancy. The ”apparition“ is revealed to be an actress looking for money at Lilac Inn and revenge on Nancy’s father for putting her in jail.