Carnival of Shadows — R.J. Ellory

Kansas, 1959. When a travelling carnival appears overnight, the townsfolk of Seneca Falls are entranced. But the circus brings more than just magic and illusion to the small town: a dead man is discovered beneath the carousel. For FBI Special Agent Michael Travis, the world is clear cut. But there are a lot of grey areas in this case. The carnival folk are unwilling to answer a straight question and they begin to challenge Travis's once unshakeable faith in solid facts and hard evidence... As the investigation turns ever more disturbing, Travis is forced to question everything he believes in as a dark and horrifying conspiracy comes to light.