Showing Wait Until Midnight by Amanda Quick

Adam Hardesty has a serious problem. The secrets of his past are in danger of being exposed, and in the course of investigating his would-be blackmailer, he discovers the dead body of a prominent psychic. To make matters worse, her house has been torn apart, and the diary containing Adam's secrets is missing. His only lead is a list of the psychic's last visitors. The most likely suspect is a woman named Mrs. Caroline Fordyce, whom he confronts in her parlour, only to discover an inconvenient attraction to the beautiful young widow. Alarmed by Adam's insinuations and questions, Caroline concludes that she must conduct her own investigation - if she can discover the true killer, Adam will have no reason to expose her connection to the dead psychic, which would cause a scandal she and her aunts could ill-afford. Besides, her life has been boringly uncomplicated for too long, and the exciting tension she feels around Adam presents a welcome alternative to her mundane daily routine. But as Caroline and Adam journey deeper into the shadowy world of psychics, mediums and con artists, they find that the only ones they can count on are each other.