 Returning to an earlier time period in Pernese history, the author brings the earlier conflict of Thread reappearing in the Second Pass.The book is set about 250 years after the Landing (the original settlement on Pern) and consequently it only features characters which do not appear in other books of the series.Following in the footsteps of the novels that established the background of the colony, the book exposes the incremental loss of technology due to the hardships of thread, and inevitable progress towards the more feudal society shown later in the series timeline.