While visiting Omaha, NE, Nick stumbled upon a small plaque on the side of a building. It read:
"In the sky over 50th and Underwood, a Japanese balloon bomb exploded on April 18, 1945. The incendiary device flared brightly in the night, but caused no damage."
From there, we fell down the rabbit hole. The story eventually brought us to the top of a high desert mountain in rural Oregon, and eventually into the studio at Radiolab.