In the summer of 1982, hospital emergency rooms in the San Francisco Bay Area were suddenly confronted with mysteriously ofrozeno patients u young men and women who, though conscious, could neither move nor speak. Doctors were baffled, until neurologist J. William Langston, recognizing the symptoms of advanced ParkinsonAEs disease, administered L-dopa u the only known effective treatment u and ounfrozeo his patient.Dr. Langston determined that this patient and five others had all used the same tainted batch of synthetic heroin, inadvertently laced with a toxin that had destroyed an area of their brains essential to normal movement. This same area, the substantia nigra, slowly deteriorates in ParkinsonAEs disease.As scientists raced to capitalize on this breakthrough, Dr. Langston struggled to salvage the lives of his frozen patients, for whom L-dopa provided only short-term relief. The solution he found lay in the most daring area of research: fetal-tissue transplants. The astonishing