Chronicle... chronicles (sorry, I had to) what happens to three high school students after finding, and being exposed to, something that changes them. The 'something' is never fully defined but it's safe to believe that it most likely is extra-terrestrial. Whatever it is, by interacting with it the three young men develop powers.
The three young men come from different life paths and are motivated by different forces. Andrew (played by Dane DeHaan) comes from a home with a terminally ill mother and an abusive alcoholic father. Andrew is painfully introverted and has a lot of pent up anger. He, and his two friends, show how the powers they gain can be shaped by who they each are and how they are treated in the world. This component makes the story very easy to relate to. I couldn't help but wonder how I would change if I gained the same kind of power.
What really makes the movie pull you in and gives it the feeling that it could really happen is how it is filmed. Every, and I mean every, frame of the movie is shot from a camera that exists in the physical space of the story. There is no 'window into this world'. We are in it. Andrew decides to start filming his life, then we have that angle of the story. It gets particularly creepy/awesome when he can manipulate the camera with his powers thereby not carrying it in his hand and having it float around him. Other shots are from security cameras, mobile phones or other characters that have video recorders. It's very well pulled together- very fluid.
The special effects and cinematography create our current day world with super powers that we know can't exist but look like they do, and naturally so. It was haunting.
The 'something' that caused the catalyst is never explained. The ending implied there could be a follow up but I hope there isn't. Sometimes ending on a mystery is a good thing. It was for this movie, easily a 9/10.