The Haunted Hotel. A Mystery of Modern Venice

Is there no explanation of the mystery of The Haunted Hotel? Is The Haunted Hotel the tale of a haunting - or the tale of a crime? The ghost of Lord Montbarry haunts the Palace Hotel in Venice - or does it? Montbarry's beautiful-yet-terrifying wife, the Countess Narona, and her erstwhile brother are the center of the terror that fills the Palace Hotel. Are their malefactions at the root of the haunting - or is there something darker, something much more unknowable at work?