The Optimen, who are distinguished by genetic excellence and exercise absolute dictatorial control over Earth from an enclave in North America, hold global society in stasis, both politically and through continuous manipulation of the human genome.

They are self-selected; their metabolism responds to the life-extension enzymes available to all members of society - which normally increase lifespan to around 400 years - by inducing true biological immortality.

Only a small minority of the Folk is permitted to reproduce, and that only under strict supervision—the vast majority are "Sterries," kept sterile through an ever-present prophylactic gas.

The adulation is however not universal; an anti-Optiman resistance exists, in the form of the "Parents Underground" and the "Couriers," both networks sponsored by the Cyborgs, mechanically-enhanced humans who had lost a war for control of Earth to the Optimen in the distant past.

The extraordinary social control of the Optimen - who have deliberately stunted technological progress - is such that culture is largely indistinguishable from that of the late 21st century.

Most of the book takes place in the "Seatac Megalopolis"—apparently incorporating present-day Seattle and Tacoma — and the Optiman enclave in the Great Lakes region.

During the procedure, he is shocked to discover that the embryo has qualities not seen in millennia; superior genetics in the areas of intelligence, plus vocation for immortality and full fertility.

Obligated to destroy it, Potter is surprised to find himself unwilling to do so, aided by the on-the-spot collusion of one of the nurses who sabotages the record of the operation.

Allgood, Boumard and Igan arrive at the Hall of Counsel for an audience with the Tuyere after Tachy-Security monitoring detects something suspicious during the Durant embryo "cutting."

They meet with the cyborg Glisson, who informs them of events, tells them that a strange external force had (beneficially) interfered with the cutting process of their embryo, and orders them to stay put.

The Durants, Boumard and Igan (their cover blown) and a gagged Svengaard are moved out of Seatac in a hover-truck driven by a cyborg, later revealed to be Glisson.

Calapine and Schruille decide to henceforth run Tachy-Security themselves, finding themselves oddly stimulated by the prospect of an even more active involvement in violence.

Glisson's gloating is cut off when a biological solution is proposed: Svengaard believes that he will be able to stabilize the Optimen, and introduce the beneficial mutations of the Durant embryo on a wide scale, giving the Folk a lifespan of at least 12,000 to 15,000 years—longevity without the pernicious ossification of immortality.

Continuing a theme present in many of Herbert's other works, the novel is principally concerned with the problems inherent in or caused by the inflexibility of a static system.

A number of Herbert's other common themes pop up, including his interest in complex, rigidly codified or ritualized behaviors, reflected in the precise etiquette expected of those granted an audience with the Tuyere.

Herbert's interest in exotic forms of communication takes the shape of the secret language of the Couriers, conveyed through subtle palm pressures during handholding.