Michael McDowell's Blackwater I: The Flood

At the crest of the worst flood in Perdido, Alabama's history, mysterious newcomer Elinor Dammert is rescued from the uppermost floor of an abandoned hotel. The town soon grows to love Elinor in spite of her unspoken past and her eccentric habits, and Oscar Caskey, head of the town's most powerful and influential family, soon takes her for his bride. But Oscar's mother, greedy and controlling Mary-Love Caskey, recognizes in Elinor a will as powerful as her own, and begins to suspect that Elinor's origins are more sinister than anyone can imagine.