Middlemen: The Brother's War
Since their creation the middlemen have been allied with the highmen, but there have always been those who believed the middlemen were to much like their eternal enemies the lowmen to be trusted while others were jealous of their destiny to end the great war.
Now, due to the questionable death of two members of the highmen’s council Cheen, who believes that the middlemen are a test of the highmen's purity. He believes that if the highmen exterminate the middlemen they will prove their unwillingness to accept anything short of perfection. But others believe that love is more important than perfection and that everyone has value. The leader of that faction is Cheen's younger brother Chart.
A battle between the highman factions would be bad enough, but through trickery Cheen is able to capture the immensely powerful wizard’s keep from the middlemen without a fight forcing them to go to the only people in the world strong enough to help them, the lowmen.
The middlemen are able to convince them to join the battle with the warning that once the Middlemen are gone Cheen will turn the power of the keep against the lowmen. Leading to a battle that no one can win and no one can afford to lose.