If you have nothing left to lose and also a huge rage in your belly, you can become very, very dangerous. Harry Brown is a widower and his only friend is brutally beaten to death by a gang. He has nothing left. And that's why he's cleaning up his act. Instead of resigning himself to a quiet retirement, the former Royal Marine takes out his gun once again and teaches the violent scum in his neighborhood to be afraid. The tough guys quickly stuck the arrogant laughter in the throat, because Harry still knows exactly how it's done. A man sees red, blood red!