The White Dragon (Dragonriders of Pern: 3)

Never has there been as close a bond as the one that exists between the daring and adventurous young Lord Jaxom and his extraordinary white dragon, Ruth. Pure white and incredibly agile, Ruth is a dragon of many talents, though almost everyone on Pern thinks he is a runt who will never amount to anything.But Jaxom knows better, knows he can teach his dragon to fly and destroy the deadly silver Thread that falls from the sky. Disobeying all rules, Jaxon and Ruth train in secret. Their illicit flights seem but a minor disobedience - until they find themselves in the path of danger and in a position to prevent the biggest danger of all...