Detective Elijah Baley investigates the murder of an offworlder in Spacetown. In the opinion of the Spacers, the murder is tied up with recent attempts to sabotage the Spacer – sponsored project of converting Earth to an integrated human/robot society on the model of the Outer Worlds.

To search for a killer in the City's vast caves of steel, Elijah is assigned a Spacer partner named R.Daneel. That's Robot Daneel. And notwithstanding the celebrated Three Laws of Robotics, which should make such a murder impossible, R.Daneel is soon Elijah's prime suspect

This is the first of Isaac Asimov's robot novels.

The Three Laws of Robotics

• A robot may not injure a human being, or through inaction, allow a human being to come to harm
• A robot must obey the orders given it by human beings except where such orders would conflict with the First Law
• A robot must protect its own existence as long as such protection does not conflict with the First or Second Law