NEW YORK - There are reflective people who take things in, and radiant people who beam light out.

Tom Cruise is definitely of the second kind. His eyes sparkle, his teeth sparkle, and so does his eternity ring, a wedding band inset with serious diamonds at its equator. In his presence, an SPF 30 sunblock is recommended, to protect against starburn.

At 46, the eternally boyish actor who has, incredibly, been top box office for 25 years, is as polished and gleaming as a freshly buffed Vince Lombardi trophy. And for one who has a reputation as a control freak, Cruise comes across as unguarded and open about his life.

"A bright candle" is how filmmaker Bryan Singer (X-Men) describes the actor and executive producer of Valkyrie, a white-knuckle thriller about the real-life German officers who conspired, and failed, to assassinate Adolf Hitler in 1944.

"Alfred Hitchcock explained the difference between surprise and suspense," says Cruise, casual in an untucked navy-blue shirt and dark pants. "If a bomb under a table goes off, that's a surprise. But if we know that the bomb is under the table but not when it will go off, that's suspense."

"We literally have a bomb under the table," he says. "In movies you want to create drama. In the case of Valkyrie, which is a conspiracy thriller, the drama is actually true."

Valkyrie takes its name from the mythical handmaidens who carried fallen heroes to Valhalla. In the movie Cruise plays Claus von Stauffenberg, hero of the German resistance, who lost an eye, a hand and two fingers on his other hand in battle, and with great difficulty crafts an explosive and smuggles it into Hitler's quarters.

An Oscar contender in a holiday movie season where everyone, it would seem, dies but Hitler, Valkyrie is one in a clutch of Nazi-era movies (Defiance, The Reader, The Boy in the Striped Pajamas) coming to your arthouse or multiplex.

Cruise is as puzzled as everyone else by what may have spurred this boomlet. It may be, he allows, that the generation that resisted Hitler or survived his death camps is dying out, and thus there is an urgency to debrief these last eyewitnesses to history.

"I met with von Stauffenberg's daughter and other family members to get a measure of the man," he says.

When you think Tom Cruise movie, you think unprincipled contemporary youth who grows a conscience by the final reel (Risky Business, Rain Man, Jerry Maguire).

Yet Valkyrie is one in a trio of Cruise historical dramas - along with Born on the Fourth of July and The Last Samurai - in which real warriors reconsider the morality of war. What makes Cruise the right man for the job, and different from most of his peers, is that even when his character is introspective he takes action. Cruise emotes with his whole body, not just from the neck up. He radiates electricity.

For him it's more about the mental workout than the physical one. "The fun thing about movies," he says, "is that I get to enter these historic worlds, to learn history from the figure's viewpoint."

He met with Vietnam vet and antiwar activist Ron Kovic while preparing for Born on the Fourth of July. And read up on the French mercenary Jules Brunet, on whose life his character in The Last Samurai is based.

"When you have a real-life figure to play, you have more clues to approach the character," Cruise notes, "but greater responsibility to present the figure accurately."

For an actor who has worked in every genre except the musical, Cruise's filmography is remarkably thin on comedy. (Risky Business and Jerry Maguire are coming-of-age stories with comic passages.)

Yet on Dec. 11, Cruise received a Golden Globe nomination for his jaw-droppingly funny turn as Les Grossman, profane, insane and unchained studio mogul in Ben Stiller's Tropic Thunder. Though not exactly known for his sense of humor on or offscreen, Cruise revealed the funny bones beneath his character's hairy, prosthetic forearms.

"It's not that dying is easy and comedy hard," Cruise says, referring to the deathbed crack often attributed to English actor Edmund Kean. "It's that it's hard to find one."

"Ben and I" - that would be Stiller - "are working on a concept called Hardy Men," about the Hardy Boys all grown up. "And Will and I" - that would be Smith - "are looking for a comedy we could do together."

But that's the future and this is now, Cruise's reconciliation tour. He is making amends for his irrational exuberance in 2005, when he jumped the couch on Oprah, effusively declaring his love for Katie Holmes, now his wife and mother of his third child, and delivered a heated anti-anti-depressant rap to Matt Lauer on Today.

He's been looking at the videotapes and has apologized (to Lauer) for his "arrogance." He admits to recently reviewing his TV appearances from as far back as 1983. "I just saw my first [Entertainment Tonight] interview and I was sweating, it's hilarious," he says. At the time, he adds, ET dismissed him as "just a teen idol."

Valkyrie's release marks Cruise's 27th year as a professional actor, his 25th as a star. He made his debut in Taps (1981) opposite Sean Penn. If an actor doesn't care whether he alienates his audience and a star does, then Penn is an actor and Cruise, though he has played unsympathetic in The Color of Money, Collateral and Magnolia, is undeniably a star - with an actor's chops.

In any generation it's hard to sustain 25 years at the top of the entertainment industry, even harder today when the industry is so diffuse.

Was it intuition or good advice - or a combination - that has guided him?

"Gut instinct," he blurts. "And the decision not to make Top Gun 2.

"I wanted to challenge myself, I wanted to work with Martin Scorsese [The Color of Money] and Oliver Stone [Born on the Fourth of July]," he says. "I was incredibly fortunate that I got to work with the likes of Paul Newman and Dustin Hoffman."

Cruise laughs heartily telling about stalking his future Rain Man costar Hoffman in 1984 in a restaurant in New York during Hoffman's storied Broadway run in Death of a Salesman.

"He was so cool, wearing this hat and eating Cuban food, and I went over and said hello and said something like, 'You look at Risky Business and know how we were indebted to The Graduate.' I never dreamed we'd work together."

This fall, Cruise has been stalking another Broadway actor in an Arthur Miller revival - his wife, Katie Holmes, who is in All My Sons.

"I've seen it more than 20 times," he says proudly, "and Suri" - their 2-year-old - "goes to hang out in the dressing room."

And his older two children from his marriage to Nicole Kidman, Isabella, 16, and Connor, 14, where are they?

"They're home-schooled, so they can travel wherever we are," he says. "They've been raised on sets and in makeup trailers. We're nomadic."

Let other celebrities rent villas when they're on a movie set. Cruise, Holmes, et al. are bunking down in the Union Square bachelor flat Cruise bought in 1983 with his Risky Business earnings.

"It's small, but we're snugglers," he says. "We're all on top of each other."

For an instant he looks down at his ring, which boasts so much ice that you would not be surprised to find it in a highball. "I'm not a jewelry guy," he says, almost apologetically, "but I love being married."