Shortly after Fiona's return to Fort Weyr three Turns older & wiser her queen Talenth is infected with the dreaded sickness that has consumed so many of Pern's precious fire-breathing dragons. Talenth's recovery & the recovery of all the other dragons of Pern is delivered by the unflagging efforts of Lorana & Kindan at Benden Weyr
- but their one vital clue is only bought with the loss of all the dragons of Telgar Weyr. Fiona is sent to relieve the distressed weyrfolk of the now
- dragonless Weyr. When her queen Talenth rises to mate Fiona finds herself not only Telgar's senior Weyrwoman but in the center of the dilemma that confronts all Pern
- how can the one thousand fighting dragons do the job of three thousand? & if they can't how long will it be before all of Pern is consumed by Thread?