Darren Aronofsky's new movie trailer: a bizarre bird mutation, or just a dream?S

Everybody connected with Darren Aronofsky's next film has been all but mute about what's happening to star Natalie Portman. And now the first trailer raises more questions. Is Black Swan a psychological ballet thriller, or a surreal story about mutation?

As you can see, Portman is quite a different sort of dancer at the beginning of this trailer than she is by the end. So what do you think — is this all in her character's head or actually happening? It's unlike Aronofsky to make a film without some sort of strange twist, but then again things in his films are seldom as they first appear.

Here is the official synopsis:

Nina (Portman) is a ballerina in a New York City ballet company whose life, like all those in her profession, is completely consumed with dance. She lives with her obsessive former ballerina mother Erica (Hershey) who exerts a suffocating control over her. When artistic director Thomas Leroy (Cassel) decides to replace prima ballerina Beth MacIntyre (Ryder) for the opening production of their new season, Swan Lake, Nina is his first choice. But Nina has competition: a new dancer, Lily (Kunis), who impresses Leroy as well. Swan Lake requires a dancer who can play both the White Swan with innocence and grace, and the Black Swan, who represents guile and sensuality. Nina fits the White Swan role perfectly but Lily is the personification of the Black Swan. As the two young dancers expand their rivalry into a twisted friendship, Nina begins to get more in touch with her dark side - a recklessness that threatens to destroy her.

In theaters December 1, 2010