For sixty years Barbara McClintock grew corn and read it the way other people read a page. What she found in it should have rearranged biology in 1951. Genes are not beads fixed on a string. They move. They switch one another on and off. A genome is not an instruction manual handed down intact from one generation to the next but a text that revises itself while it is being read.

The story usually told about her is a story of persecution: the brilliant woman ignored by small men for thirty years until Stockholm finally called and made her the only woman ever to hold an unshared Nobel Prize in Physiology or Medicine. It is a satisfying story. It is also mostly untrue, and what lies underneath it is stranger and far more useful.

McClintock was no outsider. She was one of the most decorated geneticists of her generation, elected and honored and applauded by colleagues who admired her enormously and could not follow a word she was saying. She had found something true for which her field owned no vocabulary, and no amount of eminence will buy you a word that has not been invented yet.

Here is what she saw in a cornfield in the summer of 1944, why two decades passed before anyone could hear it, what four generations of popular accounts have gotten wrong about her, and what it actually costs to be right too early.