Tony Stark attempts to integrate an artificial intelligence of unknown origins into his defence network and unwittingly creates an artificial life form intent on the destruction of the human race.
Age Of Ultron follows the rather hackneyed formula of “A.I. tasked with the defence of the human race decides the best course of action is to exterminate it” of The Terminator and, well, nearly every other si-fi story written since Isaac Asimov took up his pen. The result is Thor flying around smashing up robots, Hulk jumping around smashing up robots, Iron Man flying around shooting robots, Black Widow running around shooting robots and Hawkeye running around…well, you get the idea. It follows the blockbuster sequel formula of action / one liner / action / one liner ad infinitum to the letter and while the theme of a peace keeping force creating the conflicts it is supposed to be resolving is an interesting one, Joss Whedon is so wrapped up in setting up spin offs and sequels that he forgets to include a coherent plot; for this reason the film feels more like an episode of one of his TV series than a motion picture. As ever, the action is well staged and the one liners amusing but the lack of any real depth to the characters and their motivation makes it all rather uninvolving.
Fine if you just want to switch off your brain and sit through a computer generated firework display but those expecting anything more will be disappointed.