Vol 30, No 5. Contents: 6 • Re Rays • [Editorial (Astounding)] • essay by John W. Campbell, Jr. [as by The Editor] 9 • Opposites—React! (part 1 of 2)? • [Seetee] • serial by Jack Williamson [as by Will Stewart] 33 • The Analytical Laboratory: October 1942 (Astounding, January 1943) • [The Analytical Laboratory] • essay by The Editor 33 • The Analytical Laboratory: November 1942 (Astounding, January 1943) • [The Analytical Laboratory] • essay by The Editor 34 • Backfire • novelette by Ross Rocklynne 44 • The Search • novelette by A. E. van Vogt 60 • Nothing But Gingerbread Left • short story by Henry Kuttner and C. L. Moore [as by Henry Kuttner] 69 • Barrius, Imp • [Anachron] • novelette by Malcolm Jameson 83 • The Cave • novelette by P. Schuyler Miller 92 • Get Out and Get Under (Part 2 of 2) • essay by L. Sprague de Camp 100 • Time Locker • [Gallegher (Henry Kuttner)] • novelette by Henry Kuttner [as by Lewis Padgett] 112 • Elsewhen • [Fergus O'Breen] • novelette by Anthony Boucher 127 • Book Review (Astounding, January 1943) • essay by John W. Campbell, Jr. 128 • Brass Tacks (Astounding, January 1943) • [Brass Tacks] • essay by uncredited 128 •  Letter (Astounding, January 1943) • essay by E. Everett Evans 129 •  Letter (Astounding, January 1943) • essay by George Holman 129 •  Letter (Astounding, January 1943) • essay by Arthur W. Saha [as by Arthur Saha].