Part Two: When Tudor polymath John Dee meets a man who claims he can speak with angels, his path to understanding the universe suddenly becomes clear. At their instruction, the pair begin searching for the fabled philosopher's stone. But the angels grow increasingly demanding, and soon Dee must confront a terrible ultimatum.

Centuries later, a strange incident in a French town suggests that angels may still be with us.

For a list of sources, see the show notes at timharford.com