written by Anne McCaffrey
This title remains unpublished in this form.
short story in the Dragonriders of Pern series
short story
Analog editor John W. Campbell requested "to see dragons fighting Thread", Pern's menace from space, and he also suggested time travel. In response, McCaffrey wrote a short story titled "Crack Dust, Black Dust", which was not separately published, but provided crucial material for the novel Dragonflight.