On September 30, 2007, Richard Dawkins, Daniel Dennett, Sam Harris, and Christopher Hitchens sat down together for the first and only time, with cameras rolling and no moderator. The resulting two-hour conversation, filmed at Hitchens's home, became the raw material for this film, which cuts the discussion down while keeping its unscripted texture. The four talk about how each of them arrived at public atheism, what backlash they faced after publishing bestselling books within a few years of each other, and where they actually disagree, including friction over tone and tactics. Dennett pushes for patience and argument, Hitchens for direct confrontation, while Dawkins and Harris weigh in from their own angles on religion, science, and politics. There's no narrator and no reenactment, just four writers talking through ideas that made all of them famous and controversial at the same time. It stands as the only recorded meeting of the group before Hitchens's death, which gives the footage a documentary weight beyond the conversation itself.