Soon after publication of On the Origin of Species, Charles Darwin received a letter that deeply unsettled him. He had expected outrage and accusations of heresy, but this letter was different: it accused him of taking credit for a theory that wasn't his. Yet when he tried to trace his intellectual forebears, he found that history had already forgotten them... Rediscovering Aristotle on the shores of Lesbos and Leonardo da Vinci fossil hunting in the Tuscan hills, this is a masterful retelling of the collective daring of a few like-minded men, whose early theories flew in the face of prevailing political and religious orthodoxies and laid the foundations for Darwin's revolutionary idea.