Book excerpt: At the height of the roaring 1920s, the ex-frontier town of Denver, Colorado, emerged from the postwar boom as the future of the American city. But the slick facade of progress and opportunity masked a murky stew of organized crime, elaborate swindles, and widespread government corruption. One man risked everything to alter the course of history. Rookie district attorney Phillip Van Cise was already making national headlines for a new brand of law enforcement. Employing military intelligence tools he'd developed during the Great War - wiretapping, undercover operatives, communication intercepts - Van Cise crippled the criminal empire of Lou Blonger, an ex-lawman who had risen from petty scam artist to master of the Big Con. But Van Cise had even darker, more malevolent forces on his radar. The Ku Klux Klan had emerged as a shockingly mainstream middle-class movement, employing anti-immigration scare tactics, encouraging vigilantism, and instigating culture wars, all while claiming to