J.B.S. Haldane, scientist extraordinaire—born in Britain yet spiritually bound to India—remains one of the most enigmatic geniuses of the modern era. Here is a man who saw action in two world wars, engaged in the most radical politics of his day, conducted groundbreaking scientific research, and wrote with flair and conviction—yet Haldane’s universe remains shrouded in mystery. Award-winning author Samanth Subramanian’s latest offering undoes this travesty. Besides shedding light on Haldane’s contributions to genetics and evolutionary biology—he was the first to calculate the rate at which mutations occur and accumulate in genes—the book illuminates Haldane’s inner world—his towering intellect, his radical vision of society, his provocative philosophy, and his attempts a wrestling with the essential moral questions that scientific progress must raise.