Earth's mightiest heroes (Iron Man, Thor, Harry Dean Stanton, etc.) must once again band together to answer the ultimate question: How old is Ultron? Also, who is Ultron, again? A Google search performed by the Hulk (he keeps breaking the keyboards, so this takes half the movie) reveals that Ultron is 47 and some type of mouth-breathing robot.
"FOOL MORTAL! FOR A MERE $100 MORE YOU COULD HAVE GOTTEN ULTRON 6S!"
The Avengers defeat Ultron, but ... surprise! Ultron was Loki in disguise! Yes, for once Loki is the villain of this Marvel thing! Being defeated was part of his plan, which somehow leads to a sky battle with some aliens over, let's say, New Jersey. The stakes have never been this high for Marvel's heroes, except for all those other times when the stakes were exactly this high. In another unexpected plot twist, Thor removes his shirt and it turns out he's totally ripped -- so much so that Ultron/Loki's circuits overload from all the hotness, and he's not even a real robot.
"Those words are as follows. Ham. Shoe. Elbow. Funky. And corn."