"Mirror Image" is a science fiction short story by American writer 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 many 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 many letters from readers stating "Thanks, but we mean a novel". Source: Wikipedia (en)