Unpaginated HTML ebook; also available as plain text (iso-8859-1 & us-ascii); all formats available from Ebook #24529.
Produced from Astounding, November 1959. Two illustrations from that issue, credited to Martinez, are included in the HTML version.
The listing before the text gives the author's name as Gordon Randall Garrett, but the listing within the text gives it as Randall Garrett.
"Produced by Greg Weeks, Stephen Blundell and the Online Distributed Proofreading Team at http://www.pgdp.net".