In March 2006 the world's richest men sipped champagne in an opulent New York hotel. They were preparing to compete in a poker tournament - with million-dollar stakes. At the card table that night was Peter Muller, who managed a fabulously successful hedge fund called PDT. With him was Ken Griffin, who was the tough-as-nails head of Citadel Investment Group. There, too, were Cliff Asness, the sharp-tongued, mercurial founder of the hedge fund AQR Capital Management, and Boaz Weinstein, chess "life master" and king of the credit-default swap. Muller, Griffin, Asness, and Weinstein were among the best and brightest of a new breed, the quants. Over the past 20 years, this species of math whiz had usurped the testosterone-fueled, kill-or-be-killed risk takers who'd long been the alpha males of the world's largest casino. The quants believed that a cocktail of differential calculus, quantum physics, and advanced geometry held the key to reaping riches from the financial markets. And they helped create a digitized money-trading machine that could shift billions around the globe with the click of a mouse. Few realized that night, though, that in creating this extraordinary system, men like Muller, Griffin, Asness, and Weinstein had sown the seeds for history's greatest financial disaster.