Oz: The Great and Powerful

When Oscar Diggs (James Franco), a small-time circus magician with dubious ethics, is hurled away from dusty Kansas to the vibrant Land of Oz, he thinks he’s hit the jackpot—fame and fortune are his for the taking—that is until he meets three witches, Theodora (Mila Kunis), Evanora (Rachel Weisz) and Glinda (Michelle Williams), who are not convinced he is the great wizard everyone’s been expecting. Reluctantly drawn into the epic problems facing the Land of Oz and its inhabitants, Oscar must find out who is good and who is evil before it is too late. Putting his magical arts to use through illusion, ingenuity—and even a bit of wizardry—Oscar transforms himself not only into the great and powerful wizard but into a better man as well.

the official version from trailers.apple.com on November 14, 2012

A charlatan in Kansas, who is part of a traveling circus, goes on an odyssey when he mysteriously lands in Oz and later becomes the Wizard of Oz.

from deadline.com on October 6, 2010

The story of the Wizard before he became the Wizard Of Oz. He is a circus wrangler transported by tornado to the world of Oz where the inhabits mistake him for a know-it-all.

from deadline.com on June 15, 2010

The story centers on the wizard character from “The Wizard of Oz” and how he came to sit behind the curtain.