New York, Doubleday, 1952. First Edition. First Impression. Hardback. A very good copy. A lovely association copy inscribed by Asimov to David Hartwell (editor and all round SF superstar). The inscription reads 'To David Hartwell / With Best Wishes / Isaac Asimov'. The third (published) in Asimov's [Galactic] Empire series. An early work and a classic of the genre. The jacket has a couple of tears exceeding 20mm, further wear to the spine tips and some soiling to the rear plate. The boards are slightly discoloured to the top edge. A decent copy and an important association. Cover art by George Guisti [6539, Hyraxia Books].