 Using the dragons' ability to travel "between" different times, dragonwoman Xhinna, rider of blue Tazith, and her group of blue and green dragonriders go back in time to some uninhabited islands, hoping to return in sufficient numbers to be able to fight Thread effectively.This weyr is unusual because breeding is normally the preserve of the much larger gold and bronze dragons.Xhinna, the first female weyrleader and the first female rider of a blue dragon, must overcome challenges to her leadership.