Lullaby follows the life of Carl Streator - an over the hill reporter whose family mysteriously died years prior. After being assigned to investigate a rash of mysterious infant deaths, he discovers the killer of his own family - an ancient culling song published as a lullaby in a simple children's book. Carl sets out to destroy existing copies throughout the world but is surprised to learn that the people he once trusted to stop the deaths may be involved in the heinous acts.