Rin is a survivor of the first Mongol invasion of Tsushima Island, Japan, in 1274. She is the sole survivor of her village, and watched as the Mongols brutalized her parents and then burned their home down around them. Rin survived because she had help: a girl her own age appeared immediately before the Mongols reached her home in Sasuura village. This girl possessed a great secret which was soon revealed to both Rin and her attackers: she had a third...