Across North America elevators move 325 million passengers every day, and most of the time, people don't give them a second thought. In "Trapped in an Elevator," NOVA reveals the secret life of these ubiquitous machines. How do elevators work? Are they safe? (Yes.) Why are so many people afraid of them? (We'll find out.) NOVA's cameras ride the world's fastest elevator to the top of the Burj Dubai, the world's tallest building, and test whether the Burj's elevator system is ready for the task of moving people to unprecedented heights. On the other side of the world, NOVA follows one of the thousands of elevator maintenance crews in Manhattan that keep New Yorkers moving up and down every day. Then, at the Otis Test Tower -- a 28-story high-rise that's the most over-elevatored building in the world -- we experience pure elevator terror as a test elevator is sent into free fall. Once brawny but simple machines, elevators are getting a brainy makeover. Computer controls, like the ones that run the elevators at the Marriot Marquis in Time Square, are getting passengers to their destinations faster and more safely than ever before. But will the elevator-wary be comfortable handing over the reins to computers? Everybody has an elevator story. What's yours?