Actor Nicholas Hoult and actress Rooney Mara have been signed on to star in "The Discovery", a sci-fi love story set in a world where the existence of the afterlife is scientifically proven. "The One I Love" director Charlie McDowell is helming the film, said The Hollywood Reporter. McDowell and Justin Lader, who co-wrote The One I Love together, have reunited to write The Discovery. Hoult, 25, plays the son of the man responsible for this discovery, and Mara, 30, plays a woman he falls in love with whose life is tinged by a tragic past. Shooting is slated for January in Rhode Island.