Remember the fairy tales your parents used to tell you before bedtime? Those weren't stories -- they were warnings. Nick Burkhardt thought he prepared himself for the realities of working as a homicide detective until he started seeing things he couldn't quite explain. When his ailing Aunt Marie arrives, Nick's life turns upside down when she reveals they are descendants of an elite group of hunters, also known as "Grimms," who fight to keep the balance of humanity safe from the supernatural creatures of the world. As Nick digs deeper into her past, he realizes that he will have to shoulder the responsibility of his ancestors -- and contend with a larger-than-life mythology of the Brothers Grimm that is now all too real.