written by Anne McCaffrey
published in 1983 by Del Rey Books
novel no. 7 in the Dragonriders of Pern series
novel
Set in the Pern universe
The story involves a deadly disease that nearly wipes out the Pernese population. Moreta is a weyrwoman at Fort Weyr who sets out to save the human population, racing against time itself. The follow-up novel, Nerilka's Story, tells the tale of the same event from a different perspective.