The Voices at the End of the Road - Ghosts of the Big Thicket

The Whitfield Estate is hidden deep in the Big Thicket outside of Soda, Texas. This reclusive family brood amassed their oil and timber fortune over four generations, and now that it's been done, they have become painfully aware of how isolated and broken they are as a family.   Tessa Nettles, fresh from college, is hired as the estate manager. But her main role is to help the youngest Whitfield, Caroline, have a more normal life.
She has been cloistered away at Whitfield for the whole of her first fourteen years. Now, her oldest brother, Grayson, wants to make a happier life for her than he and their brother, Travis, had. But first, he will have to deal with the strange lights that fall from the sky over the Trinity River and their connection with the mysterious voices at the end of the road. The voices of entities that have secretly been Caroline's only friends her whole life.
Are these ghostly entities dangerous? Will they want Tessa gone from Whitfield? Will Old Gullah Woman and Preacher Man be allowed to stay on in the rundown river cabin, stirring up the waters and calling down the mysterious lights? Or will the Whitfield matriarch run them off, even after their Gullah potions kept her husband alive two years longer than the doctors could have? Will Tessa bring harmony to the estate, or set off a competition between the brothers that has the potential to destroy the Whitfields completely?