Dragonriders of Pern, The return to Terra.

The change of the path of the red star was a successes and pern is freed from its dangerous enemy but unknowingly to the people of pern the red star now passes Earth. The humans on earth who are not used to the dangers of thread fall send out a signal with technology fare beyond that of pern asking for help. But the riders of the weyrs are unwilling to help so a single bronze rider and his dragon takes it on themselves to try and save Terra. As they jump between traveling to Terra they meat the gril Willow whom they bring back to Pern to stand for a clutch so she can gain a firebreathing dragon to fight thread with back on earth. But things docent's go after the plan when Willow impress a golden queen.

A fan-fiction of Anne McCaffrey's books Dragonriders fo Pern, the universe of Pern belongs to her as well