Filmmaker Guillermo del Toro says his upcoming directorial “Nightmare Alley” will rated “double R”.The new project, which is del Toro’s follow-up to his Oscar-winning film “The Shape of Water”, will feature Bradley Cooper and Cate Blanchett in the lead.The filmmaker will direct the film from a script he has co-written with Kim Morgan. It is based on the 1946 novel of the same name by William Lindsay Gresham.In an interview with Collider, del Toro shared a few details about the project, saying the film will be a “really dark story” without any “supernatural elements”.”Well what it is is that book was given to me in 1992 by Ron Perlman before I saw the Tyrone Power movie, and I loved the book. My adaptation that I’ve done with Kim Morgan is not necessarily — the entire book is impossible, it’s a saga.”But there are elements that are darker in the book, and it’s the first chance I have –in my short films I wanted to do noir. It was horror and noir. And now is the first chance I have to do a real underbelly of society type of movie. (There are) no supernatural elements. Just a straight, really dark story,” the director said.The book is about Stanton Carlisle, an ambitious young con-man who teams up with a female psychiatrist who is even more corrupt than he is.At first, they enjoy success fleecing people with their mentalist act, but then she turns the tables on him, out-manipulating the manipulator.When asked about the film’s rating, del Toro said, “Big R. Double R.”The director will also produce the project with J Miles Davis. The movie will be distributed by Fox Searchlight.