Note: "Arkham House Science Fiction Novel" appears at the bottom of the half title page, and there is an "SF" near the top of the spine. Sheldon Jaffery in The Arkham House Companion discusses the reason for the "SF" and speculates that it indicated a new Science Fiction line. Jaffery also states that this is the only book that Arkham House ever marked as such. So, this appears to be a series of one.