The family plot a novel

"At twenty-six, Dahlia Lighthouse is haunted by her upbringing. Raised in a secluded island mansion deep in the woods and kept isolated by her true crime-obsessed parents, she is unable to move beyond the disappearance of her twin brother, Andy, when they were sixteen. After several years away and following her father's death, Dahlia returns to the house, where the family makes a gruesome discovery: buried in their father's plot is another body--...