Of all the things humans rely on plants for-- sustenance, beauty, fragrance, flavor, fiber-- surely the most curious is our use of them is to change consciousness: to stimulate or calm, fiddle with or completely alter, the qualities of our mental experience. Pollan dives deep into three plant drugs-- opium, caffeine, and mescaline-- and explores the cultures that have grown up around these drugs. He examines the powerful human attraction to psychoactive plants, and the equally powerful taboos with which we surround them. The result is a unique blend of history, science, memoir-- and participatory journalism. -- adapted from jacket.