In the newest entry in this action-packed series, Namioka's two wandering samurai are shipwrecked on the northern island of Ezo (modern Hokkaido) and find themselves trying to avert a battle between a new Japanese settlement and the indigenous Ainu. As in their previous adventures, Zenta and Matsuzo have a mystery to solve: a bear has been attacking the Japanese, and it soon becomes evident that it has been trained to do so. By whom? There are suspects on both sides. The two ronin are given complex character traits--young Matsuzo's optimistic enthusiasm plays off Zenta's moodiness and experience, often to comic effect--and the author throws up a few red herrings to complicate the otherwise simple, quickly paced plot. There is some violence--the culprits and several bears die--but it's emphasized less than the theme of working toward peace.