As the trial concludes, the defense is denied the right to call scientific experts. In a brilliant legal maneuver, Drummond calls the prosecutor, Matthew Harrison Brady, to the stand as an expert on the Bible. Under relentless questioning, Drummond forces Brady to admit that a 'day' in Genesis could have lasted millions of years, exposing the logical flaws of strict biblical literalism and causing Brady to break down publicly.
Cates is ultimately found guilty, but the judge, wary of the political climate and media presence, issues a mere $100 fine, which the defense immediately appeals. Denied the opportunity to give his triumphant closing speech, Brady attempts to deliver it to a chaotic, dispersing courtroom, suffers a massive stroke, and dies. Hornbeck mocks the deceased Brady, but Drummond fiercely defends his former friend's past greatness, rejecting Hornbeck's heartless cynicism. In the final scene, Drummond picks up Darwin's Origin of Species and the Bible, weighs them thoughtfully against each other, claps them together, and puts both into his briefcase, symbolizing that faith and science can coexist.