Walked into the jungle, the desert, or the fog, and never came back.

If the world's greatest mystery writer vanished for eleven days and registered at a hotel under her husband's mistress's name, what exactly was she solving?

The FBI sent the fastest plane ever built to find him, and it was defeated by clouds.

He kept his route secret so no rival could reach the city first. More than a hundred people have since died trying to find him.