1967 Charlottesville, Virginia.

Stevenson has had an idea.

He's at the locksmiths, Brown's Lock and Safe, to be precise,

and no, he hasn't lost his keys.

This is an experiment.

He's buying a padlock, a combination padlock.

$16.95, so about 160 bucks today.

Not cheap.

But then he wants this lock to last a long time.

I mean, maybe for eternity. So it's worth getting a good one.

The professor heads back to his office and I think it's fair to say he's feeling pretty excited

about all this. He's been inspired by an Englishwoman and Mrs. Greaves, whose dead husband

left behind a safety deposit box,

a locked safety deposit box with a combination lock. She wants to get into it, see if there's

anything valuable inside, but there's a problem. Mrs. Greaves doesn't know the combination,

so she and her son try various random sets of numbers. They try and they try,

but it's useless, a waste of time. Until...

One day, Mrs. Greaves had the experience of seeming to be in contact with her deceased husband,

who was trying to give her the correct combination.

When she tried the sequence of numbers which came to her in this fashion,

the lock opened and the lid of the box sprang up.

So, yeah, this gives Stevenson his bright idea. He arrives back at his office with his brand

...