The untold story of how a German cult, pioneering psychologists and secret LSD experiments sparked a gathering of hippie tribes in 1967 San Francisco that would change the world.

COPENHAGEN — It’s Wednesday, a sunny morning after an abundance of Scandinavian clouds, and I’m gawking at a wooden flower pot nurturing enough home-grown marijuana to cloud Keith Richards’ brain.

Not all of San Francisco’s hippies live by flower power. Last week the city’s psychedelic enclave, the Haight-Ashbury district, was shaken out of its roseate trance by the brutal murders of two hippie ...

Researchers studying the multifarious effects of LSD had new and disturbing reports last week. Not only does LSD expose unstable trippers to the risk of a psychotic break. Not only does it break down ...