If you're in search of a really creepy book (one which I wouldn't suggest trying to read right before bed), give Christopher Buehlman's debut a try.
Those Across the River (Ace, 2011) is the story of washed-up academic and WWI veteran Frank Nichols, who takes possession of a family house he's inherited in the backwoods town of Whitbrow. Nichols decides he'll write a book about the ancestor whose plantation had been in the neighborhood, believed murdered at the hands of his own slaves in the aftermath of the Civil War.
But Whitbrow's not the quiet river hamlet it seems to be; there's something out there (yes, it's across the river), and Frank's arrival sets into motion a chain of events with dramatic consequences for the entire town.
An eerie page-turner with its fair share of unexpected plot twists, interesting characters, and an unconventional and unexpected explanation.