Roses Are Deceiving: A Gothic Mystery in the Tradition of Victoria Holt — B.J. Conner

The mysterious disappearance of Lady Kathyrn Pendul has Scotland Yard baffled and left without evidence against the only suspect, her husband, Sir Royden. In a desperate attempt to gain evidence, Inspector Wesley persuades Elizabeth Courtland, under the guise of a governess, to enter into Sir Royden's household, and act as a spy.
Beth, a young lady of independent means and self-proclaimed spinster, a rarity in Victorian England, was ready for a change and the lure of the unknowns she would face at Pendmore Estate intrigued her.
Beth quickly becomes embroiled in the family's affairs and not only finds herself the victim of a sinister plot of murder and deceit, but realizes that she has succumbed to that absurd notion called love.