Charmed is not what you think. Not what I thought, anyway. I thought it was a silly piece of fluff aimed at pre-teen girls who think quality drama means pretty actresses, cute boys and a series of glamorous outfits. I was convinced it was a throwaway hour of guiltless fun that had more in common with the cheesiness of Sabrina the Teenage Witch than it did with the allegory and far-reaching emotional resonance of Buffy the Vampire Slayer.

But as I found myself waiting more and more impatiently for the next episode, the somewhat unpleasant realisation hit me that there must be something else to Charmed besides the fashion. And I was determined to figure out what it was.

There is no doubt that Charmed is pitched at a younger demographic than Buffy. Its storytelling technique is far simpler, information is more directly conveyed, and the dialogue is littered with pop-cultural references that even I felt a little old for. But this does not make it fluff. Its stories may be simply told, but they are not simplistic. In fact, they have the potential to create surprising emotional resonance.

It is light, though, and has an extraordinary commitment to fashion, but Charmed knows its audience and it knows exactly how to connect with it. Through its three protagonists - Paige (Rose McGowan), Piper (Holly Marie Combs) and Phoebe (Alyssa Milano) - Charmed tackles questions of duty, obligation, family, responsibility and sacrifice. Big questions. And it handles them pretty well.

The Halliwell sisters are the "Charmed Ones", three witches destined, according to an ancient prophecy, to fight evil and protect innocents. Which they generally manage to achieve with only slight complications. The magic in Charmed, despite its at times earth-shattering implications, is very low-key. There is not much blood, dismemberment or disembowelment. Which is fine, because, as in Buffy, magic is far less important than the personal lives of the characters. Thus magical elements (a demon, a curse) are usually wrapped up within the episode, while personal stories run through the series.

Charmed is really about the battles fought by young women trying to make their way in the world. How do they balance the responsibility of being a Charmed One with the desire to chase spunky boys? And what about a career? Is it even a possibility? Or will they end up, as Phoebe’s newspaper colleague warns, chasing work success at the expense of everything else, including love? It is nice to see a show even bothering to ask these questions, especially when so many series are content to hold an audience to the next commercial break, let alone into next week.

Charmed puts these questions to three very different female characters, then sets them off to find the answers themselves. It’s a woman’s world at the Halliwell manor, and though the men - Leo (Brian Krause) and Chris (Drew Fuller) - are "whitelighters", there to guide and protect the sisters, their advice is only occasionally listened to, rarely heeded and often mocked.

The girls’ late grandmother (Jennifer Rhodes) and magical guide of sorts (she reappears from time to time) thinks "men are like utensils: you use them, wash them and throw them in a drawer until you need them again". But the Halliwell sisters disagree and spend most of their time dating boys, talking about boys and addressing boy problems. For Paige and Phoebe, this is a seemingly endless parade of romantic trivialities. But Piper, the eldest and most mature, is a single mother trying to find a man who will love her and her young son, Wyatt. Her son, by the way, is intent on scaring off would-be suitors with a fairly dodgy magical trick.

But no one watches Charmed for the magical effects. Like the best fantasy or science fiction, the magic serves to create a different narrative space, to allow the writers to play with their characters in new ways. What happens when characters completely lose their inhibitions? With the freedom to introduce something like a spell, Charmed is able to answer this.

And if the spell is cast at the precise moment that all three sisters are contemp-lating a life away from the family home, it creates not only comedy in the sisters’ almost immediate transformation into slathering hornbags, forbut also reveals that all three are wondering if there might not be more to life than being a Charmed One. And that is a big moment. It is not gritty, realist drama, but it is honest and emotional and often nicely subtle. It also carries a positive message: the girls are strongest when they invoke the "Power of Three" - a simple allegory for the ethos that supporting your family and friends is the most important thing.

And, of course, there is the fashion, and it is unfailingly spectacular. Sending the sisters back to the ’60s has value for the story, but it also gives the girls a chance to dress up in the most garish ’60s costumes the costume department could lay its hands on.

That’s Charmed for you: nice and light, lots of fun, and a warm message at the end. And with so many questionable role models out there for pre-teen girls, that is not such a bad thing.