The story of the Dragons of Pern has been going on for a long time. I recall reading the first volume way back in the 1970s. Now the story continues in Dragon’s Time by Anne & Todd McCaffrey, due next month. According to the press release, this is the final book in the Pern saga.
“Although Lorana cured the dragons' sickness so many died from the disease that there are no longer enough dragons to fight the deadly Thread, and more dragons and their riders die each Threadfall. With their numbers dwindling, Lorana made the decision to fly forward in time in a desperate bid to bring dragons from the future to fight Thread. She knew that jumping so far in time would result in her losing her baby, but without her jump all life on Pern is doomed.”