Dragon strike (Age of Fire # 4)

After being separated by dwarf slave traders who found their nest, the brothers and sister – AuRon, the rare scaleless gray; Wistala, the green female; and Copper, the embittered cripple – are reunited. But their reunion is not a happy one, since the three find themselves at odds over the coming human war. AuRon thinks dragons should have no part of the affairs of human. Wistala believes dragons and men can peacefully coexist. And Copper has designs of his own for the world.
And the civilized humans who have turned to Copper for assistance against their savage enemies have just given him the perfect opportunity to fulfill his plans.
(from the back cover)