Bob Lee Swagger and Philip Yano are bound together by a single moment at Iwo Jima, 1945, when their fathers, two brave fighters on opposite sides, met in the bloody and chaotic battle for the island. Only Earl Swagger survived. More than sixty years later, Yano comes to America to honor the legacy of his heroic father by recovering the sword he used in the battle. Bob Lee finds the sword and delivers it to Yano in Tokyo. On inspection, they discover that it is not a standard WWII blade, but a legendary shin-shinto katana, an artifact of the nation. Suddenly Bob is at the center of a series of terrible crimes he barely understands but vows to avenge. And to do so, he throws himself into the world of the samurai. But in the end, he will succeed only if he can learn that to survive samurai, you must become samurai. If Swagger hopes to stop them, he must be willing not only to die but also to kill.