  "mirror image" is a science fiction short story by isaac asimov, originally published in the may 1972 issue analog science fiction and fact, and collected in the best of isaac asimov (1973), the complete robot (1982), robot visions (1990), and the complete stories, volume 2 (1992). after having received numerous requests to continue the story of detective elijah baley and his robot partner r. daneel olivaw, featured in his earlier novels the caves of steel and the naked sun, asimov wrote this short detective story. after the story appeared, he received several letters from readers, all of whom said, "thanks, but we wanted another novel". ==plot summary== baley is unexpectedly contacted by daneel to help resolve an authorship dispute between two spacer scientists. being spacers, neither scientist is willing to allow himself to be interrogated by an earthman, but they are willing to allow baley to interrogate their personal robots. the two robots are the same model, and their stories are mirror images of each other: each one insists that his own master came up with a key scientific insight, and that the other scientist is falsely trying to lay claim to it. clearly, one of the robots is telling the truth, while the other has been ordered by its master to lie. baley must use the three laws of robotics and his own knowledge of robot nature to determine which is which. but the answer really comes down to his knowledge of human nature. ==references==    
1972_short_stories Robot_series_short_stories_by_Isaac_Asimov Short_stories_by_Isaac_Asimov Works_originally_published_in_Analog_Science_Fiction_and_Fact