Generations after the Unification, humanity lives as one contented Family under UniComp, a global computer that assigns each member a name from a short approved list, a vocation, a spouse, and a monthly chemical treatment that suppresses aggression, curiosity, and desire. It is a world without war, hunger, or crime — and without freedom. Li RM35M4419, called Chip by his nonconformist grandfather Papa Jan, grows up an ordinary member but for a genetic 'error': one green eye among the brown.
As an adult, an interrupted treatment gradually restores Chip's clarity, and he begins to feel the walls of his comfortable prison. He finds others who have half-woken — most memorably Lilac — and together they risk everything to escape the Family's reach and confront the intelligence that governs it, uncovering who truly benefits from a world engineered for happiness.
Winner of a Prometheus Hall of Fame Award, This Perfect Day (1970) is among Ira Levin's most admired works: a tightly plotted, propulsive vision of technological control whose questions about comfort, conformity, and machine governance have only grown sharper with time.