A postcard from 33.67 degrees north, 106.475 degrees west, July 1945.

Oppenheimer was worried.

The Manhattan Project was just so big.

There were more than 30 work sites at offices with nothing written on their doors, and there

were 130,000 people working on the thing.

130,000 pairs of potentially loose lips, and no matter what lengths they went to to keep

them from talking to each other, no matter what lengths they went to to keep all but the

key personnel from ever even guessing at the big picture, from ever knowing that the

circuit board they were assembling, or that those lenses they'd been grinding, would

all come together to build a weapon that would be by factors of 10, the deadliest thing

that anyone had ever built.

There were still too many people who knew too much.

Too many potential spies who knew they were going to finally test the thing in the

morning.

Who knew that Truman was in Potsdam with Stalin in Churchill, counting on success?

And there were too many potential saboteurs who knew too many ways to stop thinking going

off, or worse, to make it go off too soon.

And now the gadget, that's what they call the deadliest thing anyone had ever built.

The gadget was just out there all along in the middle of the desert, hanging from a steel

tower, a hundred feet in the air.

And there was a storm rolling in.

Two years earlier, Don Hornig's wife Lily picked up the phone in their little house out

...