About the book (from Wikipedia):
The Lady of the Shroud is a novel by Bram Stoker, published by William Heinemann in 1909.
Rupert Saint Leger inherits his uncle’s estate worth more than one million pounds, on condition that he live for a year in his uncle’s castle in the Land of the Blue Mountains on the Dalmatian coast. There Rupert tries to win the trust of the conservative mountaineer population by using his fortune to buy them modern arms (from a South American country that has unexpectedly found itself at peace) for their fight against Turkish invasion (the story was written shortly before the Balkan Wars).
One wet night, he is visited in his room in the castle by a pale woman wearing a wet shroud, seeking warmth. He lets her dry herself before his fire, and she flees before morning. She visits several more times, all at night, and they hardly speak, but he falls in love with her, despite thinking she is a vampire. He visits the local church and finds her in a glass-topped stone coffin in the crypt. Despite misgivings he declares his love, be she living or undead, and she arranges the marriage in an Orthodox ceremony conducted by candlelight in the church one night, although he still does not know her name, and she says she must still live alone in the crypt for the present. The story then traces Rupert’s adventures that are a consequence of this romance.