Land of the Spring Dragon: A Branches Book (Dragon Masters #14)

"The Dragon Masters have defeated the evil wizard Maldred, but not before the Kingdom of Bracken was devastated by Naga, the earthquake dragon; now Drake and his dragon, Worm, must appeal to the spring dragon, Fallyn, who is their only hope of restoring Bracken before its people starve--but Fallyn lives deep inside a secret fairy world, and Drake must pass a series of tricky tests before he can even make his appeal."--Publisher's description.