It was 1981, and I was still writing Darkover short stories. Actually what happened was that Marion Zimmer Bradley was editing SWORD OF CHAOS, the second Darkover anthology. Because I lived in her household and worked as her secretary, I was helping assemble the anthology. There was a story titled "Escape" that was accepted for the anthology; but the ending of it gave me nightmares, so I wrote "Rebirth" as a sequel to it--or perhaps an antidote. I was always prone to nightmares; when I was a child I couldn't even watch The Wizard of Oz on TV without getting them.
"Rebirth" is available from Kindle.