When a county deputy is called out to an abandoned farmhouse in the cornfields of Minnesota by a couple of terrified teenagers, he finds that a body has been stuffed down a cistern. And then another, and another.

By the time Lucas Davenport is called in, the police are up to fifteen bodies, and counting. And when Lucas begins to investigate, he makes some disturbing discoveries of his own. The victims have been killed over a great many years, one every summer, regular as clockwork. How could this have happened without anybody noticing?

Because one thing was for sure: The killer has to live close by. He is probably even someone they see every day...