Time travel may still be impossible, but the Chronoscope, sensing the nearly imponderable tracks of ancient photons, allows a glimpse into any event in Earth's distant past. Historian Arnold Potterley is rebuffed when he petitions for use of the Chronoscope to study ancient Carthage. So he commissions the building of a private time-viewing machine, with unexpected results.

An expedition sets out to discover what has happened to a lost colony on a distant planet. Amongst the scientists is a strange, intense teenager called Mark Annuncio, raised to be a kind of human computer, able to make connections between different specialisms. Disliked by the crew, Mark nevertheless may be the only person capable of saving the ship when they land and scientists begin dying mysteriously.

A human-looking robot housekeeper is the latest gadget to acquire in the ceaseless battle to keep up with the Joneses. But housewife Claire Belmont starts to question the wisdom of her husband's purchase when TN3 (Tony) arrives. Can a man-like robot do everything a man can do: but willingly, obediently, tirelessly? Is a robot less than a man, or more?

Robot QT-1, aboard an orbiting space-station, controls the massive energy beam which transmits the sun's power to receivers on Earth. But QT-1 (Cutie) has some strange bees in his positronic bonnet. How could weak creatures of protoplasm create a nearly invincible, totally logical entity like himself? It is up to his human supervisors, Powell and Donovan, to convince Cutie of his niche in creation before his new robot theology becomes a threat to all life on Earth.

The positronic brain of robot RB-34(Herbie) has an unforeseen 'extra': he can read human thoughts. So his take on the First Law of Robotics ("A robot may not harm a human being or, through inaction, allow a human being to come to harm") is unorthodox: he tells human beings only what he believes will not hurt their feelings. Can renowned robopsychologist Dr. Susan Calvin 'fix' RB-34? Or are there areas of her own psyche where she would rather not hear the truth?

Earth police detective Lije Baley and his robot associate, R. Daneel Olivaw, investigate an impossible murder on a planet where physical proximity is taboo but nudity is not.