It's been two-hundred years since the deadly Thread fell like rain upon Pern, devouring everything in its path. No one alive remembers that first horrific onslaught and no one believes in its return--except for the dragonriders. For two centuries they have been practicing and training, passing down from generation to generation the formidable Threadfighting techniques. Now the ominous signs are appearing: the violent winter storms and volcanic eruptions...