Rooney Mara has joined the cast of Guillermo del Toro's Nightmare Alley. The actress has previously been rumored to be in talks to jump on board, but it is now official. The upcoming movie reunites Mara with her Carol co-star Cate Blanchett, who joined the project at the beginning of August. Bradley Cooper is taking the lead in Nightmare Alley as Stan Carlisle, a con artist who falls in love with a female psychiatrist. However, things aren't exactly what they seem as Stan has the tables turned on him.

Rooney Mara is playing Molly, "the closest thing to Bradley Cooper's Stan's true love as they take the act they learned from a circus in Chicago on the road." In addition to Mara, Cooper, and Cate Blanchett, Nightmare Alley also stars Toni Collette, Ron Perlman, and Mark Povinelli, with Michael Shannon and Richard Jenkins still in talks to join Guillermo del Toro's first directing gig since the Academy Award winning The Shape of Water. So far, there's a lot of familiar faces for the director to collaborate with again.

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Nightmare Alley is based on William Lindsay Gresham's 1946 novel of the same name about a corrupt con-man who teams with a female psychiatrist to trick people into giving them money. It's unclear exactly what Guillermo del Toro is going to do with his adaptation at this time, but it is believed that it will come with a hard R-rating when the time comes. The book was made into a movie back in 1947, but it strayed quite a bit from Gresham's source material. It is believed that del Toro will be taking his adaptation and leaning it closer to the book.

Rooney Mara was last seen on the big screen earlier this year in the starring role of Garth Davis' Mary Magdalene. However, Nightmare Alley will be a lot different from her last project. Along with the R-rating, Guillermo del Toro says that the movie will have a "really dark story," and reveals that it is, "the first chance I have to do a real underbelly-of-society type of movie." That certainly sounds intriguing coming from such a visionary director, who is also trying to get his Pinocchio project off the ground at Netflix. Though it sounds fun, it will not be a movie for the whole family. Instead, it will have dark political undertones when all is said and done.

Guillermo del Toro is directing Nightmare Alley from a script he wrote with Kim Morgan. The movie is being produced by del Toro and J. Miles Dale with TSG Entertainment, with Fox Searchlight acquiring worldwide distribution rights. Production is expected to kick off in early 2020, which means the director is probably in the pre-production stage, finalizing the script and getting the rest of the cast together. We should have more updates within the next few months. Deadline was the first to report the Rooney Mara casting in Nightmare Alley.