The Story
So naturally, the Avengers are looking for Loki's staff and raiding various HYDRA bases to stamp it all out for good. Tony Stark seems to be free of his panic attacks (seen in Iron Man 3) but not his fear of not being able to protect the world and his friends. So once they find the staff, Tony convinces Banner to tap into the power of the mystical object to find out its secrets, namely how it was able to create the Scarlet Witch and Quicksilver. And they end up creating a monster- Ultron. A robot who thinks the only way to save the world is to destroy it (you'd think they would all learn by now!)
The Stars
The characters get a chance to develop a little bit, at least the ones who haven't had their own individual series - Hawkeye, Black Widow, and Hulk. We discover a whole new side of Hawkeye who is much more likable than we had previously thought, and the idea of HawkWidow fades away and we are not sad about it. Which is really quite shocking.
The Message
But this interesting concept comes out of this movie that really stuck with me- the idea that we become the thing we fear the most and that in turn we can't tell the difference between saving and damning. The more we try to prevent bad things from happening we are actually making them happen even quicker than they would have. The idea that fear has so much power and control over us that it can destroy us.
I don't know if the film completely solved this dilemma (possibly to use it as material for the next film), but it did say one thing- you can't defeat this fear by yourself. It's not something you can hide away from and hope it goes away. You need to ask your friends and family for the support and be brave enough to open up about it. And I think this speaks to all people who suffer from debilitating fears such as depression and anxiety to name a few. We need to reach out to others for help because we can't defeat the fear on our own.
Overall
It's not one I'd want to pop in for a feel-good superhero movie, but it is one I would want to watch in succession with all of the other Marvel films to connect all of the dots and marvel at the brilliance of this complex and epic example of storytelling.