Even though Lorana cured the plague that was killing the dragons of Pern, sacrificing her queen dragon in the process, the effects of the disease were so devastating that there are no longer enough dragons available to fight the fall of deadly Thread. And as the situation grows more dire, a pregnant Lorana decides that she must take drastic steps in the quest for help.

Meanwhile, back at Telgar Weyr, Weyrwoman Fiona, herself pregnant, and the harper Kindan must somehow keep morale from fading altogether in the face of the steadily mounting losses of dragons and their riders. But time weighs heavily against them — until Lorana finds a way to use time itself in their favor.