In 1613, four low-ranking Japanese samurai, accompanied by a Spanish priest, set sail for Mexico to bargain for trading rights with the West in exchange for a Catholic crusade through Japan. Their arduous journey lasts four years, as they travel onward to Mexico then Rome, where they are persuaded that the success of their mission depends on their conversion to Christianity. In fact, the enterprise seems to have been futile from the start: the mission returns to Japan to find that the political tides have shifted. The authorities are now pursuing an isolationist policy and a ruthless stamping out of Western influences. In the face of disillusionment and death, the samurai can only find solace in a savior they're not sure they believe in.