The first episode looks at how ideas, music and lifestyles from Asia, Europe and the American left became entwined in California. It traces the roots of the hippies back to a 19th-century German sect of wandering naturalists called Lebensreform, who brought their freethinking ideas about nature to California after the Second World War. There, they merged with a growing interest in eastern mystical concepts of human nature imported to America by maverick British thinkers like Aleister Crowley and Aldous Huxley. Add to this mix a wonder drug called LSD, first developed by the CIA, and a wave of student activists and anti-war protesters agitating for revolution, and you have the astonishing story of how these forces came together to give birth to the Summer of Love in San Francisco, 1967.

The second episode explores how the Summer of Love of 1967 set in motion an era of social upheaval that pitted America's youth against its elders and how the American government responded with a series of brutal crackdowns. The hippies failed politically, but their cultural influence changed the world. Everything from the environmental movement to the explosion in alternative health practices to the birth of feminism all grew out of this moment. And most surprising of all, we trace how hippie ideas first imagined on LSD went on to shape the information age itself.