Runt the Brave (The Legends of Tira Nor, Book 1)

Driven by their blood-frenzied master, GoRec, a merciless army of rats swarms toward the underground mouse-city of Tira-Nor. The rats have come for only one reason: to slaughter the mice and seize their ancestral home. But rats are not the only nightmare to awaken in the dying days of summer. A cold and bodiless evil stalks the lonely tunnels of the city, a shadow whose presence may mean that the doom of the Ancients has risen once again.   Tira-Nor's last hope lies with JaRed son of ReDemec, a mouse so small and young even his family calls him Runt. But when the crazy old seer TaMir anoints JaRed to be the next king, JaRed's brother denounces him as a traitor and threatens to expose the prophecy at court. After all, Tira-Nor already has a king!  Surrounded by enemies too terrifying to comprehend, JaRed searches desperately for a way to save the city from annihilation. When GoRec's vast rat hordes at last descend on the plains above the city, JaRed is torn between his inner conviction that "right makes might" and the common sense that tells him victory against such terrible odds is impossible. But JaRed is about to encounter a power beyond the rat army, beyond even that of the Great Owl ... a power that will fling him into a destiny wilder than anything he's ever imagined!