On November 1, 1999, Theodore Hall, physicist and atomic spy, died in Cambridge, England. He was 74 years old. Hall, who was the youngest physician (read: prodigy) to work on the atomic project during World War II, was eventually identified as a Soviet spy in the mid-'90s. By the time of his death, he had become not only a pioneer in biological research, but a notorious "traitor." Read on below.