In Milady's Chamber (John Pickett Mysteries Book 1)

Lady Fieldhurst chose the wrong time to finally agree to a lover, as they discovered her husband stabbed to death in her boudoir. John Pickett, Bow Street Runner, questions whether her ladyship is guilty of the murder, and his superiors question his impartiality, given his interest in her. But there is the presumptive heir, near bankruptcy, and the disappearing butler, and the nocturnal visitor and ... Regency Mystery by Sheri Cobb South; originally published by Five Star