The structure of DNA proposed by James Watson and Francis Crick in 1953 was one of the most important scientific discoveries of the twentieth century, transforming biology, giving medicine new impetus, and providing a foundation for the new industry of biotechnology. James Watson's best-selling memoir of the events leading to this discovery, The double helix, has enthralled millions of readers since its publication in 1968. In this videotaped lecture, recorded live at Cold Spring Harbor Laboratory in Nov. 1999, Dr. Watson retraces those events in a very personal reminiscence of the period and the people involved. This is an account of one of the great dramas in science, told from the intimate perspective of a participant who, age 25 at the time of the discovery, has become one of the intellectual leaders of our time.