Twenty-five years ago, President Bill Clinton stood before a podium in the East Room of the White House, and, in front of an all-star lineup of researchers and dignitaries, made a historic announcement: After years of painstaking work, scientists had created “the most important, most wondrous map ever produced by humankind” — the first-ever survey of the human genome.

In his remarks, Clinton compared the achievement to the maps created by Lewis and Clark’s expedition into the American West — but maybe a comparison to the space race would have been more accurate. Because, behind the scenes, the journey leading up to that day’s announcement had been defined by nerve-wracking, cut-throat competition — a competition where every minute counted, and the future of scientific inquiry was at stake.

On this encore episode, we look back at how what started as a scientific collaboration fractured into a bitter race to finish decoding the human genome. On one side was the federally funded Human Genome Project; on the other, a private start-up called Celera; and, in between, a raucous mashup of conflicting personalities, values, and ideas that would eventually help to transform science and medicine.