Explorers are a special breed—fear of the unknown and of the awful possibilities of failure don’t seem to deter them. Perfect example: the handful of people who have explored the Mariana Trench, the deepest place on Earth.

The Backstory: Shocking Death of a Heroic 9/11 Widow
10:31

The Backstory: Technology: Where We Came From and Why We’re So Lonely
10:30

The Backstory: The London Fog That Killed 12,000
10:19