Denzel Washington isn't a young man anymore.  And yet, for his new thriller "The Book of Eli," the 55-year-old two-time Academy Award winner trained over four months with martial arts experts to play the mysterious and deadly drifter Eli. 

In a post-apocalyptic America (or what's left of it), Eli is headed west on a mission and anyone who gets in his way (mostly for nefarious reason) will pay the price. Using a samurai sword with deadly accuracy, Washington says he was aghast when he was told only his silhouette would appear in one fight scene.  His response? "'Silhouette?  As hard as I'm working you're not gonna show me after all of that? Get closer or something! Make sure they know it's me. That's me!"

It's not that Washington has an ego, but as he admittedly rubs his knee the physical requirements of shooting "Eli" and longtime collaborator Tony Scott's "Unstoppable" have taken their toll and he wants credit where credit is due.

"I think I have been in a hotel ten months this year," he says as he speaks to selected members of the press from yet another hotel in Los Angeles. "I'm just happy to be here a week."

Washington is also a producer on "Eli" and was heavily involved in script rewrites as well as recruiting his onscreen nemesis  Gary Oldman ("a real joy when he signed on," Washington says.).  However, one of the more intriguing reasons Washington took one of his rare jumps into Science-Fiction wasn't the subject matter itself, but the journey of the title character.  He observes that most of the characters he's played in his accomplished career from Malcolm X to Hurricane Carter have undergone "some sort of spiritual evolution" and Eli is no different.

"Even something as dark as 'Training Day.' The first thing I wrote on my script was 'The wages of sin is death.' In the original version of 'Training Day' they had him dying in the smallest way like you heard about it on TV," Washington says. "I said, 'No, you can't. In order for to justify living in the worst way, I have to die in the worst way.'  So, there was still in my mind a lesson to be learned there or an evolution."

Washington continues, "I think there is a somewhat similar case here where [Eli] has this mission and [it] has turned him into this violent killing machine and there is no coincidence that the moment he's about to chop whoever with this hatchet, this ax, this young girl says, 'Stop.'  Why was he sent through this town right before he makes it to where he's supposed to go?  He could have gone around and it would have been a whole other story, but in his spiritual evolution this was a part of the process. He had to go down the valley of the shadow of death."

And it turns out, in a story also recounted by directors Allen and Albert Hughes, all sorts of spirits may have been watching over the production.  During an early scene when Eli is ambushed by some thieves, the camera goes in for an intimate close up as he kills the group's leader.

"I stuck the sword into him real easy almost like a sacrifice," Washington says. "And the wind started blowing and the sand blew right over us and kept going right through the tunnel.  It was like death or something.  And I stuck with [the take] and then we cut. And everybody was like, 'Man...' And I said, 'I think we're on the right track here.'"

And considering how well "Eli" turned out, quite prophetic indeed.

"The Book of Eli" opens nationwide on Jan. 15.