The novel depicts a world where genetic selection for increased health, longevity and intelligence has become so widespread that the unmodified 'control normals' are a coddled, almost endangered minority. The control normals are preserved to maintain a backup of human stock in case the gene selection takes a wrong choice somewhere. The world has become an economic utopia; the "economic dividend" is so high that work has become optional -- a sort of welfare state for the upper middle class. The chief economic problem is in finding a way to use up the economic surplus: much goes into scientific research, but this has the side-effect of further increasing productivity a decade or three later, so long-term projects with no possible economic return are favoured. e.g. galactic astronomy.
But there's trouble: dissatisfied elements are fomenting revolution, and it's up to gun-totin' Hamilton Felix to stop them. Guns, and duels are permitted, - 'An armed society is a polite society' - except for the control normals, whose reflexes are so poor compared to current human stock that they'd be slaughtered in combat.