Could there be a surprising cameo in tonight's Agents of SHIELD?

James Spader talks about playing Ultron, Scarlett Johansson explains more about Captain America, and there are Thor TV spots. Plus details on how Gravity created its isolated space atmosphere, and Nicholas Winding Refn explains a crucial secret of his upcoming Barbarella movie. Spoilers ahead! » 10/01/13 6:00am 10/01/13 6:00am