Investigating the independent discoveries of genes and of DNA in the mid-1800s; following both trails into the 20th century, as chromosomes are discovered and the realization finally begins to dawn that genes and DNA may be related.

Joining the quest to understand the molecular biology of the gene with the famous blender experiment, which shows that DNA, not proteins, transmits genetic information; looking at five scientists who compete to solve the mystery of DNA's structure.

In a race to find the structure of the DNA, James Watson and Francis Crick get a key clue.

Because DNA is only a blueprint, the discovery of its double helix structure is just the beginning; understanding how DNA synthesizes proteins; a dark horse researcher makes the crucial breakthrough; DNA fingerprinting becomes possible in the 1980s.

Covering the Manhattan Project of DNA, the Human Genome Project, to sequence all three billion base pairs of human DNA; Francis Collins and Craig Venter compete to reach the costly goal, which requires new technologies and disputed methods.

The decoding of the human genome paves the way for Project ENCODE, which identifies functional elements in the genome; focusing on examples that are central to human culture, such as language; probing the role of mutations and nature's gene splicing.