6 • Mutually Exclusive • [Editorial (Astounding)] • essay by John W. Campbell, Jr. [as by The Editor] 9 • Clash by Night • [Keeps • 1] • novella by Henry Kuttner and C. L. Moore [as by Lawrence O'Donnell] 15 •  Clash by Night • interior artwork by Paul Orban [as by Orban] 22 •  Clash by Night [2] • interior artwork by Paul Orban [as by Orban] 31 •  Clash by Night [3] • interior artwork by Paul Orban [as by Orban] 39 • Photographic Plate Finds Kepler's Nova • essay by R. S. Richardson 40 • Shock • novelette by Henry Kuttner and C. L. Moore [as by Lewis Padgett] 41 •  Shock • interior artwork by M. Isip 46 •  Shock [2] • interior artwork by M. Isip 49 • The Analytical Laboratory: January 1943 (Astounding, March 1943) • [The Analytical Laboratory] • essay by The Editor 50 • Shadow of Life • novelette by Clifford D. Simak 51 •  Shadow of Life • interior artwork by Frank Kramer [as by F. Kramer] 54 •  Shadow of Life [2] • interior artwork by Frank Kramer [as by F. Kramer] 56 •  Shadow of Life [3] • interior artwork by Frank Kramer [as by F. Kramer] 61 •  Shadow of Life [4] • interior artwork by Frank Kramer [as by F. Kramer] 64 •  Shadow of Life [5] • interior artwork by Frank Kramer [as by F. Kramer] 67 • Evolution Designs Instinct Patterns, Too • essay by uncredited 68 • Space Fix (Part 1 of 2) • essay by R. S. Richardson 78 • In Times to Come (Astounding, March 1943) • [In Times to Come (Astounding)] • essay by The Editor 79 • Q. U. R. • [Quinby's Usuform Robots] • short story by Anthony Boucher [as by H. H. Holmes] 82 •  Q. U. R. • interior artwork by Elton Fax [as by E. Fax] 91 • Brass Tacks (Astounding, March 1943) • [Brass Tacks] • essay by The Editor 93 •  Letter (Astounding, March 1943) • essay by E. Everett Evans 95 • The Weapon Makers (Part 2 of 3) • [Weapon Shops of Isher • 2] • serial by A. E. van Vogt 97 •  The Weapon Makers (Part 2 of 3) • interior artwork by Frank Kramer [as by F. Kramer] 104 •  The Weapon Makers (Part 2 of 3) [2] • interior artwork by Frank Kramer [as by F. Kramer] 113 •  The Weapon Makers (Part 2 of 3) [3] • interior artwork by Frank Kramer [as by F. Kramer] 127 •  The Weapon Makers (Part 2 of 3) [4] • interior artwork by Frank Kramer [as by F. Kramer]