Humanly Impossible Wallpapers

Firewalkers. Sword-swallowers. A man who can hammer a nail into his nose. A woman who can hang herself from hooks. You see them, and you wonder how they can possibly do it and not get hurt. Trick photography? Well, not always. Scientists deconstruct how some people are able to do what seems impossible, explaining the unexplainable. They also talk to the people who perform these stunts to find out why, how, and maybe most important -- what made them try it in the first place?