Storm Riders (Dragon Brigade Series, 2)

Daring dragon-riders fight to save a uniquely magical world from destruction by vengeful outcasts, in Storm Riders by Margaret Weis and Robert Krammes

In a magical world, two enemy kingdoms have long sought a weapon that will win lasting dominance. But then both are attacked by the Bottom-Dwellers, bitter people whose own land was destroyed. Using contramagic strengthened by blood sacrifice, they threaten to bring down whole cities. Freya and Rosia must put aside their age-old conflict to defend themselves. As the Bottom-Dwellers' contramagic eats away the magic of the dragons that protects the world above, a former dragon-riding hero gathers a new dragon brigade, the one desperate hope of the two kingdoms to defeat the fiends who threaten their world. The new dragon brigade's high-flying heroics will be to no avail, though, unless they can uncover forbidden knowledge, long hidden by the Church.