Worlds of IF - Science Fiction: April 1967 Volume 17, No. 4
Illustrations by Gray Morrow, Jack Gaughan (at his best), Castellon. Cover by Gray Morrow (for "The Road to the Rim")

Novelettes: "Retief, War Criminal" by Keith Laumer (a "Retief" tale)
"The Ethics of Madness" by Larry Niven ("Known Space" series)

Serials: "The Road to the Rim" (Part 1 of 2) by A. Bertram Chandler ("Rim" series - begins John Grimes' career)
"The Iron Thorn" (conclusion) by Algis Budrys (book title was The Amsirs and the Iron Thorn)

Stories: "The Fantastique" by James McKimmey
"It Takes All Kinds" by Bruce W. Ronald
"The Accomplice" by Vernor Vinge
"The Purpose of It All" by W. I. Johnstone

Edited by Frederik Pohl; Judy-Lynn Benjamin is Associate editor. Fandom column by Lin Carter.