'Birdman' gets better as Andrea Riseborough joins Alejandro Gonzalez Inarritu's comedy

Well played, Alejandro Gonzalez Inarritu. The Mexican director behind tough-minded personal dramas like 21 Grams and Babel has assembled an incredible cast for his first foray into comedy, Birdman. With Emma Stone, Michael Keaton, Naomi Watts, Zach Galifianakis, and Edward Norton already on board, the latest to join is fast rising star, Andrea Riseborough.

Her name isn't nearly as big as the others, but chances are it will be seen. She's probably best known for the Madonna-directed biopic W.E., although her resume is littered with great performances in films like Shadow Dancer and Never Let Me Go. She'll jump into her first blockbuster next month opposite Tom Cruise in Oblivion, so things are certainly looking up.

Birdman has Keaton as a former actor who once played an iconic superhero, and hopes to reclaim old glories by putting on a Broadway show. Norton is the egotistical actor he butts head with, Stone is Keaton's newly rehabbed daughter and assistant, Galifianakis as the show's producer, and Watts as an actress. As for Riseborough, she plays a character named Laura, but that's all we've got so far.

Is that it? Or does Inarritu have more up his sleeve?  The film begins shooting in April.[Deadline]