In Avengers: Age of Ultron, James Spader voices the eponymous villain, an entity of artificial intelligence that can inhabit seemingly any mechanical host around the world that it sees fit; break one body and you’ll just find him in an ever bigger one. Ultron is the superhero film embodiment of the ghost in the machine. Age of Ultron’s writer-director Joss Whedon, meanwhile, is the human in the too-often homogeneous Marvel machine, packing his second Avengers film with wit, pathos (as a result of characters’ palpable emotional vulnerability), and some actual thematic thrust regarding the concepts of invincibility, the transient state of human existence, and America’s knack for trying to prevent conflicts that haven’t even started with methods that doom people anyway. The symphony of destruction works because this blockbuster behemoth has an actual soul…