In the mid-21st century, newborns in the United States are legally required to befitted with a "cyber," an electronic device that has successfully slashed crime rates by changing the thought patterns of the people who have them.
In Canada, however, cybers are still illegal. Max Wilson, the first man to successfully have his cyber surgically removed, has settled in Canada, seeking a new life and joining the fight to have the law changed in the United States. With Dr. Warren Alston, who removed his cyber and is now teaching other surgeons how to do so as well, he becomes part of an operation to smuggle devices into the US that disable cybers without surgery.
Meanwhile, Patrick Kobayashi, the inventor of the cyber, is taking an active part in Canada's election campaign in support of Richard Lane, a maverick politician intent on introducing the cyber into the Canadian landscape, against his own party's wishes.
When a mysterious man calling himself "Guardian Angel" begins threatening Dr. Alston and others trying to stop the spread of the cyber, things take an ominous turn. As efforts redouble in Canada and the United States to stop the insidious threat of the cyber, which the shocking case of one little girl shows may have horrible side effects, the mysterious Guardian Angel resorts to murder and attempted murder. The freedom of individuals to think their own thoughts hangs in the balance as events race to a frightening conclusion.
