After a vicious plague swept through the world of Pern, there are no longer enough dragons to fight off the current onslaught of Thread, the deadly spore that falls like rain from the skies and devours everything organic in its path.

Pern's last best chance to rebuild the decimated dragon population lies with a group of young dragonriders and their dragons left stranded on an unexplored island. Leadership of these dragons and riders falls to Xhinna, female rider of a blue dragon, who, as the most experienced dragonrider in the new Weyr, must earn the respect of all who follow her, as not everyone is ready to accept a female wingleader. She must solve the problem of how to get sufficient numbers of dragon eggs, although her newfangled ideas, like letting green dragons mate and lay eggs to hatch new dragons, cause uproar. All the while she must protect her people and baby dragons from the predators and, worse, traitors or all hope for Pern will be lost!