New York: E. P. Dutton & Co., Inc., 1953. Octavo, cloth. First edition. The author's second mystery. Washington, D.C. setting.

Boston: Gregg Press, 1980. Octavo, cloth. Later edition, first printing of the Gregg Press edition. Text offset from that of the 1979 Ballantine Books edition. New introduction by Elizabeth A. Lynn. "Cavism, the religion of suicide, conquers most of the world." - Gerber, Utopian Fantasy (1973), p. 159. [Reference: Anatomy of Wonder (2004) II-1185. Berger, Science Fiction and the New Dark Age, pp. 190-6. Clarke, Tale of the Future (1978), p. 106. Lewis, Utopian Literature, p. 195. Sargent, British and American Utopian Literature, 1516-1985, p. 253. Baird and Greenwood, An Annotated Bibliography of California Fiction 1664-1970 2488].