1887, the Cornwall coast

For years, rumors have flown through the village of Suttonsbury about Ashthorne Hall--that its occupants hoard pirate treasure, that a ghost walks its halls--but botanist Hyacinth Bell only cares about the estate's extensive, one-of-a-kind orchid collection. As an independent woman, she is eager to focus on her career, even if it means waiting to pursue a romantic relationship. After all, love--like an orchid--must be nurtured and tended before it can bloom.

What she doesn't expect is to be swept away by Lucas Harding, the manor's caretaker, upon their first meeting. He is handsome and charming, and the connection between the two is nearly instantaneous. Hyacinth is certain this autumn will be the season that everything good in her life takes root.

But then strange things start happening in the seemingly empty halls of the estate: unexplainable noises, items appearing then disappearing from her room, threatening messages, and glimpses of a woman in white who vanishes into the dark. Lucas dismisses Hyacinth's worries, insisting that there is no ghost at Ashthorne Hall, but she suspects he is withholding information and decides to investigate the mystery herself.

Armed with little more than her instincts and her courage, Hyacinth must venture deep into the shadows of Ashthorne Hall to uncover the truth Lucas is keeping secret before she herself falls victim to the dangers hidden in the estate.