Neurologist William Langston. His work plunged him into a medical mystery, and a hot political controversy about the ethics of medicine. In 1982 Langston was called in to examine a number of "frozen" patients, young men and women in the San Francisco Bay Area who suddenly could neither move or speak, though conscious. Langston recognized the signs of Parkinson's disease, and determined that these patients had all used the same batch of tainted heroin. Langston prescribed L-dopa, a treatment for Parkinson's which only provided short-term relief.