The Kings - The Dragon Kings, #5

At the end of the war.. Only one king will survive. Sid, Val, and Skye plunge right into the middle of the war anyway, risking everything to save the dragon races. But then the war takes a terrible twist. The White Witch turns her attention to human cities and slaughters hundreds of thousands. With the arctic and canyon dragons bearing down on the rest of the dragons and humans coming after them with new weapons, the war seems all but lost.
Will they win the war? Or will all the dragons be wiped forever from the earth?