Intermittent wipers, Lego bricks, and the smiley face came from the minds of ordinary people with extraordinary stories.

They walked through fires, faced poverty, ran for their lives, and found their fortune in gold, guns and games.

The story of the gun meant to end violence, the box that keeps hearts beating, and the printer that can build anything.

How did a waffle iron change the world of running shoes forever? Find out this and other invention secrets.

Would you inhale toxins, leap off a cliff, or shoot yourself to prove you're right? Meet four inventors who did just that.

See how crime made lucrative inventions out of the house alarm, the cash register, the Tommy Gun, and even the toothbrush.

See how the TV, speed camera, photocopier, and space telescope went from sketch drawings to life-altering inventions.

How the electric chair, the Ouija board, and other chilling ideas became million-dollar inventions.