Marvel's upcoming sequel Iron Man 3 recently started production in Wilmington, North Carolina, with two actors added to the cast. Jon Favreau is reprising his role as Happy Hogan, while William Sadler will play an unspecified character.

Back in December 2010, we reported that Jon Favreau isn't directing Iron Man 3, a job which Shane Black landed last February. The director had portrayed Tony Stark's bodyguard, Happy Hogan in both Iron Man and Iron Man 2. He returns for the sequel.

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There are no details on whom William Sadler is playing, but he was recently spotted on the North Carolina set for a costume fitting.

Shane Black co-wrote the screenplay with Drew Pearce. The story will center on Tony Stark experimenting with the Extremis technology, designed to duplicate the "super soldier" serum used on Captain America.