"Magick is as mysterious as mathematics, as empirical as poetry, as uncertain as golf and as dependent on the personal equation as love." Aleister Crowley, Magick in Theory and Practice.

To define magic is to define the universe and all it contains. Philosophy, science, religion, tool; magic is all these things, but speak to anyone who uses it and they will tell you one thing: magic works.

"Something feels wrong about this place," says David as we walk along the Beau Maris sea front under a bright winter moon, "I can sense something." A 30-year-old Barbadian computing post-graduate, David Liquoriche was once a born-again Christian. He is now a born-again magician: "Magic," he explains, "helps me to effect change without going through the normal channels of power." We are here to meet David's mentor, Andrew Stockall, and two of his magical colleagues, Alistair Burnett and Nicola Dolby. Tomorrow morning they are to perform a powerful ritual invocation of the Crowleyan goddess Babalon before the cameras of BBC's Modern Times.

It's been a wet week and weathermen predict worse to come, but the skies are clearing. "Andrew's definitely been doing his stuff," states David in matter-of-fact fashion. Our winding route takes us past an old church. Suddenly David yelps, his body convulses and he darts across the road, clearly freaked. "What was that?" I ask, somewhat startled myself. "I don't know, but it felt like a million hands running down my spine." David crosses the spot once more and the sensation returns. Try as I might, I feel only the chill of the night. We head back to our hotel. There's a huge-horned black goat's head over the lift entrance. We take the stairs.

It's past midnight now and I'm sitting in the hotel's brown-leather lounge with Andrew, Alistair, Nicola and Wally, Andrew's down-to-earth but admirably open-minded father. Although a practicing magician for almost 15 years, Andrew has only recently come clean to his dad about his esoteric pursuits, and Wally is keen to discover what it is his son has been doing. "I believe in Andrew, but I want to see this ritual for myself," he says. "Andy and Alistair can talk to me all day and all night and I'll still be none the wiser. I want what they're doing to prove itself to me."

It's Andrew, a large, engaging, voluble 34-year-old catering manager, who has drawn the others together, and he is their spokesman. As well-versed in behaviourism and personal development tools like Neuro Linguistic Programming as he is in Eastern mysticism and the Western Hermetic Tradition, Stockall comes across as a very modern magus. The others are equally defiant of occult stereotyping: Nicola has known Andrew since childhood; Alistair, a softly-spoken engineer, met him on a catering course almost ten years ago; David, a genuine Black magician, is the newest recruit. All regard Andrew as their mentor, though certainly not their master. "Andrew doesn't really teach," explains Alistair. "He'll give you a certain amount of work, then at certain points we'll make contact and see what kind of results I'm getting." In fact, once Andrew had set Alistair on the right path, he didn't contact him for 18 months: "He had to really want to do this, because it was going to change his life so much."

Andrew's own interest in mysticism took root at the tender age of 11. "I was inspired by the fantasy stories I was reading, particularly Alan Garner (best known for The Owl Service and Redshift). I then became interested in Indian mysticism and Hindu and started practicing transcendental mediation very seriously at about 15. This taught me to relax and focus, which really helped me in my difficult teenage years." His initiation came via the Golden Dawn correspondence course, based in Phoenix, Arizona and his discovery of Wilhelm Reich and The Mass Psychology of Fascism: "that explained a lot; that humans are not so removed from nature as many would have us see it." From here he became involved with the Crowleyite sex-magical order, the Ordo Templi Orientis and it was then that the penny dropped. "Basically, I'm not the same person I was 15 years ago. I started out as one of Thatcher's children, working in a London advertising firm, and was forced to see life in a completely different way - I had no choice really."

Andrew and Alistair are here because they want to bring magic out of the shadows: "We want to combine the various traditions and make magic accessible. We're going to write a technical manual for the absolute beginner. We will create angels, or astral software, which can be used by anyone to achieve all manner of results with a high degree of success."

So what is the secret, and what will the spiritual software actually do for you? A straightforward answer is perhaps too much to ask. "You've got to ease yourself into this a bit at a time," says Alistair, a note of caution creeping into his voice, "or you can get yourself into a right mess. It's a gradual peeling of the layers of the onion, removing mental blocks until you start to feel new energies working in your life. You literally will feel the energy flow - it's not like anything else you've felt. Actually making yourself plastic enough to get into these altered states of consciousness takes a long time. But the most difficult step comes afterwards - forming the Body of Light, the subtle reflection of your self."

Andrew agrees: "It's hard work and the ego doesn't like it - it tries to resist, it convulses. You will want to scream, you will do anything not to do this. Then, in the deepest state of meditation you'll find your breathing becoming incredibly shallow, and you get a sinking feeling like nothing on earth as you actually go through the death process. Then - splat - time just ceases. Everything you've ever known or felt just falls down and you're away. You're dealing with an energy that is like a lump of plasticine - you can do what you will with it."

The next step, continues Alistair, is similar to the Buddhist practice of assuming godforms: "You become the god for a while, take on some of their characteristics." It's the astral equivalent of impersonating a revered pop star or actor. You can also externalise the godform outside of your self. Chaos magicians would call this a Servitor, a term Andrew dislikes -"this isn't the magical equivalent of the Raj" - while the Quabbalistic magician would merge different energies to build an angel. "Each tradition is linked," he notes, "they're describing the same things." Ultimately, you can mould your magical forms out of anything you like, Andrew even admits to having used The X Files' Dana Scully - "just for a laugh."

So far, so good. But all this sounds like an advanced and potent form of creative visualisation. What can these energies actually do?

"Do you want dark to light or light to dark?" Andrew asks. The Dennis Wheatley in me chooses the former. "Have I ever used magic to make somebody hurt themselves? Yes. Have I ever rendered anybody impotent with magic? Yes. Have I caused someone whose drinking habits were hurting their family to hurt themselves, or just leave? Yes. It's unpleasant I know, but there are so many people out there at it who won't talk about it. Everything I've done has had a purpose. On the light side, have I healed people? Yes, of psychological illnesses, bipolar disorders, sleep disorders, tooth grinding. I did, and still do, a lot of work helping other people through my Mystic Orchard outreach service. Can we project into each other's dreams? Yes. Then there's the pure astral meeting, the projection into the Body of Light. That's when I'm all black, sitting in a tree, looking at you like this (he leers and grimaces), and you're walking along a beach, about ten feet tall. It's a strange place."

But with the belief in these abilities comes the knowledge that others have them too, and can use them against you. "I think Paul Tickell (the director for Modern Times) is under magical attack," Andrew tells me. "He's been robbed at knife point for the first time, and he hurt his back badly while on holiday. Some of the people he's spoken to in the occult world are going to be very unhappy about this programme, but we're ready to deal with whatever they can chuck at us, and hopefully the ritual will help Paul."

Magic also has its more practical applications. "When we started to write our ideas down, in September, we decided that we wanted to share them with the world and asked how best to go about it. It's now early January and here we are, preparing to go on TV and talking to you. Magic is just one way of putting your house in order."

Tomorrow's ritual will have a less clearly defined purpose. They will enact a slightly modified Enochian rite, rooted in the 16th century angel scrying operations of John Dee and Edward Kelly and reappropriated by the 19th century Golden Dawn. "It's a technically difficult ritual, and some people have gone a bit crazy doing it, but we know what we're doing. I'm going to enter the aethyric realm ARN, meet the goddess Babalon in the form of indivisible bliss and wisdom and invoke her into myself. Imagine one great fertile womb into which you can plant any thought you want, and that thoughtform will gain seed and manifest. We're going to bless the island, ourselves, and everybody watching. We're going to send that divine ray of pure harmonising energy right through all of you. It may cause some changes to occur in your life, but you will love those changes."

"I guarantee, you won't forget tomorrow," adds Alistair. "Kelly had a vision of Babalon, but didn't write down what he saw. It seems he stopped magic very quickly afterwards. People fear her because of that - she has something of a bad reputation. Our own favoured archetype for her is a huge, thunderous swan. So keep an eye out!"

"Well, the weathermen got it wrong," remarks a hotel waitress the next morning, "they said it would be rain and gales all day." The sun is shining from clear blue skies as the film crew load up the Land Rover that will take us to Llanddwyn Island. Its guardian, St Dywnwen, is the Welsh patroness of lovers, so hopefully she'll be sympathetic to what is due to take place. If we can get in the car, that is. The key has bent firmly out of shape since the previous night. After considerable struggling to straighten it out, we set off to catch up with the magicians, who have gone on ahead to make their preparations.

We reach the island's entrance, where a bemused ranger greets us. He'd had some trouble with the magicians' car; the key to the automatic gate wouldn't work, so they'd parked and walked. I remember something Alistair had said the night before: "There's definitely a magnetic component to this. I've fused lights, my car CD player, the telly turns over on its own." The gate opens fine for us and we drive out to the island.

It's a place of wild beauty, overlooking a large seal-swum bay and the dark, distant shadows of the Black Mountains. The rough, flat moorland at its centre is thrust violently upwards on the island's outer rim, the hills giving way to craggy rocks, which disappear into the sea like the spine of a great sea beast. In a small bay lie organic-looking globs of bright pink quartz, like petrified lumps of flesh or a giant's blancmange. A large stone crucifix holds court from the highest spot on the island, overshadowing an older Celtic cross near where St Dwynwen once had a well, now reverted to a spring and currently flooded. Legend has it that the island holds the ruins of a small town but, other than a modern lighthouse, some small outbuildings and the shell of an old chapel, this isle belongs to nature.

A scenic viewpoint is decided on and the magicians identify their cardinal points, marking out a magical circle with coloured pegs. The rest of us locate ourselves carefully around it - we have been warned of the consequences of stepping into the circle, particularly for sensitive recording equipment. For some reason Wally, who had seemed so keen to view the ritual the previous night, opts to help keep curiosity seekers at bay. The magicians take their places. I had hoped for robes, but despite an epée and a small ceremonial dagger, the four of them could be ramblers.

And so it begins. Andrew and Alistair perform a Lesser Banishing, cutting pentagrams and hexagrams into the air at each compass point, magically sealing themselves off from the outside world. Andrew intones in the long syllables of Enochian, calling out to various Egyptian gods for assistance and protection. The four take turns reading segments, occasionally making shapes - stars and crosses - with their bodies so that a distant observer might think they were performing gentle aerobics. As the magicians progress through the chants and invocations, their voices take on a richer, deeper quality, even Nicky loses his shrillness.

After about 30 minutes of ritual preparations, Andrew is ready to take on Babalon herself. As he begins to pace around within the circle I notice great shafts of light piercing the clouds over the bay and, for a moment, a strange, inhuman shape silhouetted against the distant cross. To my combined relief and disappointment, it takes on the form of a walker taking a breather. "Are you happy with your vanity?" Andrew/Babalon asks us in a vaguely threatening whisper, "are you sincere?" Muttering all the while to himself, Andrew paces tighter circles. His eyes bulge alarmingly and his face turns beetroot red. There are no swans, but a fighter jet thunders overhead and suddenly Andrew is crawling along the ground towards Alistair, chattering quietly all the while. They converse, disjointed as if in a dream, then Andrew is back on his feet. Babalon has left the building. They perform more banishings to remove any unwanted cosmic residue and retreat to the ruined chapel, clearly exhausted, their eyes glazed over with the thousand-year stare of those who have spoken with angels.

They're still shattered when I approach 15 minutes later. Alistair is dry-heaving. "I'm off my head! I don't know what I'm doing," he squawks, before lapsing into incoherent mumbling. "It was a very strange energy, bliss, intoxicating bliss. I was swaying about, having trouble staying on my feet. You tend to forget what you're doing, what's going on."

"The air becomes semi-solid, almost like looking through a snow storm," says Nicky of the space within the circle. Andrew agrees: "I could hardly see much of what was going on - you were like a flickering black candle. There's a shimmering haze around the circle and the sky and sea were an amazing shade of red. The energy's all over you, like two harrier jump jets passing straight through your solar plexus. I feel totally drained and post-orgasmic." He admits that he managed only a partial possession, feeling uncomfortable going all the way in front of so many people: "I'd have been all over Alistair if I had!"

They all feel that the ritual was a success, despite a couple of small gaffs - pentagrams drawn the wrong way round, that sort of thing. Alistair looks at me somewhat ominously: "I drew a pentagram over you, it may have some dramatic effects later on. You may not necessarily like them." If the dramatic effects include the stinking cold that I took home with me, then he's right, I don't like them.

Three months down the line all concerned remain happy and healthy, but I can't say I've felt Babalon's presence in my own life. But then, would I even recognise her if I passed her in the street? It seems that a key part of living magically is heightening one's sensitivity to meaning, in much the same way, as Paul Tickell points out, that many artists do. The world of the magician is an enclosed one, hermetically sealed, inside which the laws of nature, and the nature of belief are wilfully transformed. But does it work for those outside the circle? What about those alleged magical attacks? Says Tickell: "Of course there are logical explanations for what happened to me, but I will say that the knife used in the mugging wasn't an ordinary one. It had an almost ceremonial look to it..."

Through Tickell and their proposed book, the magicians are taking magic to the masses. Whether they succeed depends on whether the masses want magic, and whether the world of magic wants them.