The Disappearance of Lady Frances Carfax (S05E01)

While enjoying a getaway in the picturesque Lake District, Watson encounters the mysterious Lady Frances Carfax, troubled by the spectral presence of a horseman. Intrigued, Holmes travels to join Watson, only to find that Lady Frances has mysteriously disappeared. Determined to unravel the mystery, Holmes delves into the circumstances surrounding her vanishing, becoming increasingly intrigued by the ghostly figure that seems to haunt her.