LSDs inventor Albert Hofmann called it "medicine for the soul." The Beatles wrote songs about it. Secret military mind control experiments exploited its hallucinogenic powers. Outlawed in 1966, LSD became a street drug and developed a reputation as the dangerous toy of the counterculture, capable of inspiring either moments of genius, or a descent into madness. Now science is taking a fresh look at LSD, including the first human trials in over 35 years. Using enhanced brain imaging, non-hallucinogenic versions of the drug and information from an underground network of test subjects who suffer from an agonizing condition for which there is no cure, researchers are finding that this "trippy" drug could become the pharmaceutical of the future. Can it enhance our brain power, expand our creativity and cure disease? To find out, Explorer puts LSD under the microscope.