Examines the life and accomplishments of twentieth-century scientists James Watson, an American zoologist, and Francis Crick, an English chemist, the men responsible for cracking the genetic code and discovering the molecular structure of DNA, and includes a time line, and a selection of primary source transcriptions and images.

Human mystery -- Two unusual men -- The world of the 1950s -- Ups and downs -- The pieces come together -- The basics of DNA -- The years that followed -- How DNA is used today -- Glossary.