When Mona Friedman (Julianne Moore) is cast in a bit part at a small community theatre, she transforms from a shy, unassuming housewife into a zealous method actor willing to do anything to protect the artistic integrity of her role. Her uncompromising approach puts her at odds with the show’s irritable and domineering director, Jerry (Paul Giamatti) who is on a mission to rein in Mona’s growing ego. As their visions collide, Mona’s newfound confidence begins to transform her life in ways she could have never imagined.