I haven't seen an out-of-nowhere phenomenon like Twilight since the day I visited the set of a then-obscure new TV show called The X-Files, whose producer told me he was praying to equal the ratings of Unsolved Mysteries. Peter Facinelli was similarly unaware of what awaited when got cast as Twilight's kindly vampire Dr. Carlisle Cullen. "I don't think anybody ever knew it was gonna be this big."

I knew it. The Twilight books were already huge. Why? Because, as The Atlantic's professional girl-intellectual Caitlin Flanagan explains in "What Girls Want," Twilight is about "a boy who loves a girl so much that he refuses to defile her, and [a] girl who loves him so dearly that she is desperate for him to do just that, even if the wages of the act are expulsion from her family and from everything she has ever known."

You can see why girls stampeded to see Facinelli's fanged yet friendly crew. "We don't want to hurt people. It's kinda like trying to domesticate a lion and turn him into a cat -- trying to deny our very nature. We're trying to live among humans and trying to live a more vegetarian lifestyle than most vampires I've seen." Dr. Cullen recommends that vampires feed on animals instead of humans.

There's a similar idea in TV's True Blood, but the overall idea of Twilight is utterly different. "I saw like five minutes of True Blood, and it seems a lot campier from what I've seen. Twilight tries to be more --- I hate to say 'reality-based,' because it's a vampire show. It definitely takes itself more on a reality level. We took our work seriously. It's a good story, it goes back to Romeo and Juliet, two lovers that can't be together. I think people relate to their first love."

Girls have dominated the initial audience for the film, but what's in it for the guys? Isn't it just a chick flick? "It's not!" says Facinelli. "A specific example: my brother-in-law, a real guy's guy. When he went to Twilight he brought his iPod with him, because he said, 'I love you, but....' He thought it was gonna be a sappy love story. But he loved it! He kept poking my sister, and saying, 'God, I really thought I was gonna hate this!"

What the guy liked was the film's under-publicized action part. "This other vampire coven comes to town saying, 'Why are you feeding on animals instead of people?' They kidnap the girl, and our family has to go get her back." Studies show that the number-one male fantasy is to save somebody's life (preferably female and as pretty as Kristen Stewart).

Now Facinelli is gearing up for the Twilight sequel and a career that has not exactly entered a twilight period lately. "I've been working for 15 years, so that's a success in itself." But the other kind of success -- launching a megamillion-dollar movie franchise -- that's kind of nice, too.

My advice to guys is, even if you feel resistant, let her drag you to see Twilight. Otherwise you might wind up dumped like the guy in the stupid yet completely au courant YouTube clip "Once You Go Bat."