The Black Charade — John Burke

In 1880s England, Dr. Caspian and his wife Bronwen both have genuine psychic abilities, which they keep secret. Even so, they've gained a reputation as investigators of so-called psychic phenomena, exposing a number of fraudulent mediums. In their latest adventure, they're consulted by prominent politician Joseph Hinde, whose beautiful daughter Laura has become strangely withdrawn. Her secret assignations have led him to suspect that she might be attending séances in an attempt to contact her dead mother, whom she had adored.
Asked to rescue her from the clutches of evil charlatans, the Caspians uncover a tangled trail of people dying in strange and horrible circumstances. Dr. Caspian suddenly realizes that not only is Laura's life in danger from an age-old spirit...but Bronwen's as well.

Another first-rate novel of horror by a masterful storyteller!