The notion of the thoroughly modern Tom Cruise in a period piece may strike some as a mission impossible: The last time he went historically epic was in 1992's blah immigrant ode ''Far and Away.'' But that was two Oscar nods and a mouthful of braces ago. Here, Cruise is Nathan Algren, a tortured U.S. Civil War vet who is invited by Japan's emperor to modernize his army. But once there, Algren becomes increasingly sympathetic to the ancient samurai, whose old-fashioned ways the emperor wants to eradicate. With conflict looming, Algren is forced to choose a side. Cruise's own allegiance is clear. ''I have a tremendous affinity for the code of the samurai,'' says the star, who took the part after walking away from the Jude Law role in the more American period opus, ''Cold Mountain'' (which stars ex Nicole Kidman). ''It's about honor. Compassion. Loyalty. Those things always get me in my life.''
Edward Zwick has always dug those things too. A nut for Japanese culture since college, the ''Glory'' director spent almost a decade developing ''Samurai,'' a fact-based fiction inspired by the life of Saigo Takamori, who was known as ''the last samurai.'' ''Gladiator'' scribe John Logan helped him research and fashion the story; Marshall Herskovitz (who created TV's ''thirtysomething'' and ''Once and Again'' with Zwick) provided screenplay polish with input from Cruise, who's also a producer. ''The film doesn't presume to be a history lesson,'' says Zwick, ''but you can have it both ways. It's a rousing adventure, but it's also about an entire society in crisis.''
Zwick began shooting last fall in Japan before moving to L.A., where old Tokyo was re-created on the Warner Bros. backlot. In January, production moved to New Zealand -- doubling for the Japanese countryside -- for cast-of-hundreds battle sequences. While Zwick had to learn to direct Japanese-speaking actors, Cruise had to master elaborate fight choreography; one scene required 38 separate maneuvers in one sustained take, all while dodging swords swung at his $20 million mug.
But nothing taxed him more than growing a mangy, period-appropriate beard. ''There was a lot of discussion -- beard, no beard. One day, I just decided to grow it,'' says Cruise. ''[But] I was concerned, man -- there were certain patches where I couldn't grow it.'' It eventually filled in, and so far he's kept it, in case reshoots are needed. ''Penélope likes it,'' adds Cruise, referring to girlfriend Penélope Cruz. ''But I'm looking forward to cutting some of it off.''
The Killer Moment ''A visually stunning sequence,'' says Cruise, in which his character encounters an army of fearsome samurai emerging from the fog -- and realizes that his allegedly superior forces are destined to lose horribly.