The moment feels prescient now. McCarthy's brief, profane appearances in This Is 40 crack the movie open. With the new comedy Identity Thief, she gets a starring role. It might be great. It might be terrible. Either way, it's hers, and for now at least, she's a puppet off the strings, landing parts she wasn't supposed to get in big movies where no one expects her to fade into the background, playing characters who need best friends of their own.