Detective Del Spooner (Will Smith) is not a fan of robots and on the surface looks like he does not believe they are as benign as advertised. The top inventor of the robots Dr. Alfred Lanning (James Cromwell) commits suicide (presumably). He leaves a message that has Spooner assigned to the investigation. Why Spooner?
Spooner gets suspicious and will not leave the suicide lie. Naturally his boss Lt. John Bergin (Chi McBride) says drop it. The head of the robotics firm says drop it. Susan Calvin (Bridget Moynahan) knows he is crazy and says drop it. Even his own mother says drop it.
V.I.K.I. (Fiona Hogan) is mistrustful of Spooner's motives.
So does Spooner finally come to his senses and drop it?
Is he paranoid or are his suspicions founded?
This is definitely a Will Smith vehicle with a few CGI robots thrown in. The title of course came from a Robert Heinlein novel. From here we have all the standard clich' and scenarios as a boss who does not believe the same and kowtows to authority, an obvious bad guy, a girl that puts her foot in everyone mouth, standard red herrings, and much more.
Still this is great fun and Will makes the movie. There are plenty of "action" scenes, "stay in the car" scenes, "shower" scenes, "chase" scenes, and even cliffhangers.