While F'lar convinces the Lord Holders to patrol their lands for possible Thread burrows, Lessa and F'lar's Wingsecond, F'nor, go back ten years to test the feasibility of starting a new Weyr on the long-abandoned Southern Continent to allow the hatchlings from Ramoth's first clutch to mature and help with Threadfall in the current time. While talking with F'lar, Masterharper Robinton plays an old Teaching Song called the Question Song, written about the disappearance of the other five Weyrs four hundred turns earlier. Hearing the song, Lessa realizes that the missing Weyrs had come forward to their time to help Pern in its current need. Using an old tapestry showing Ruatha Hold as it existed centuries ago as a guide, Lessa jumped backwards to the end of the 8th Pass and the start of the Long Interval (the time between Passes is called an Interval and usually lasts about 200 Turns; a Long Interval lasts around 400 Turns.) and convinces the Fort Weryleaders, T'ton and Mardra, to talk to the Telgar, Igen, Ista, and High Reaches Weyrleaders and join her in coming to the future (Lessa's present) and defend Pern from its ancient scourge, Thread.