John Hancock is a superhero with superpowers (he can even fly) who uses them to protect people against crime, to fight criminaks and saving lives. But he becomes alcoholic and clumsy and while doing these good actions he also damages and destroys property which makes people to hate him. He saves PR expert Ray Embrey of being hit by an oncoming train and some odd friendship is born betwenn them since Ray tries to make him a good hero again. Ray introduces him to his wife and his son Aaron who is Hancock's fan. An odd relationship starts also between Hancock and Mary, Ray's wife, who is discovered to be also a superwoman who had lived with Hancock many centuries ago. But she dislikes his behaviour and their relationship is broken with everything turning to normal and she returning to her husband Ray. This movie is full of fighting and violent scenes technically very good.
