So Superheroes instead of fighting the evil rising, they just started fighting each other. That's a dessert for some villains out there. Tony decides that the avengers should be kept in check under the Government while Cap refuses to do so. And thus the war begin between the team itself.
This video I came across Youtube is a fan made video imagining what happens if one of the Ironman's suit ends up in the hands of an ordinary civilians. Tony busy fighting his own team mates, didn't notice a suit missing. The video is actually like a trailer. Guess who's after the suit... It's not Tony..
You can check their work on their youtube channel ( https://goo.gl/vKWNAU )