Questions that outlived the people who raised them.

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 never let anyone watch him work.

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.

The French army once used a man who could swallow live puppies whole as a courier, hiding documents in his stomach.