It's the cult that loves to flaunt its celebrity members while remaining obsessively secretive.
At the weekend members flocked from all over the planet to the home of UK Scientology - the middle-England commuter town of East Grinstead - for the annual address by its leader David Miscavige.
And The Sun was able to wander in unchallenged for a peek into the sect's mysterious world.
We heard the bizarre declarations of Miscavige - including his insistence that the Holocaust was started not by Nazis but by SHRINKS.
Although the Saint Hill Manor HQ is brimming with security guards, we are welcomed inside and follow the surging crowd entering an enormous tent at the back.
It is a mix of pensioners, teenagers, families in their Sunday best, women in cocktail dresses and men in sharp suits. It could be a country fair or a public school open day.
But this is Scientology's 28th International Anniversary Event, where followers celebrate the sect founded by L Ron Hubbard.
Inside you are expected to sit according to nationality. There are large American, German and French contingents. We join the group waving Union Flags.
The stage is flanked by two golden statues of horses mid-gallop and behind is a giant image of a globe - as if to say, "This is ours".
To the left hangs a portrait of Hubbard, his arm resting on another globe. The message is clear.
The crowd is at least 3,000-strong and the mood is one of anticipation.
The tent is buzzing with excitement. But amid the party atmosphere, serious-looking individuals dressed all in black patrol the aisles.
It feels as if you are being constantly watched.
As the lights go down we hear a stirring mission statement: "We are dauntless, we are defiant, we are resolute."
Then we are greeted by the great man himself, Tom Cruise's buddy and the sect's global leader - David Miscavige.
He is given a rock star welcome, but delivers an oddly emotionless speech.
From the start we are bombarded with information. There are flashing lights, booming sound effects, and statistic after statistic, some hard to believe.
Miscavige tells us Scientology is present in 126 nations - from Sri Lanka to Vietnam.
He boasts about it rescuing thousands of addicts, although what they're addicted to is not made clear.
He uses odd terminology at one point, saying Scientology is responsible for "disseminating peace".
For two hours, Miscavige bangs on about the evils of psychiatry, claiming it is out to drug our kids for money.
He declares: "Psychiatry has no scientific grounding.
"Taking their drugs is like playing Russian roulette."
He insists that Scientology is out to "de-rail an upside-down Utopia where human sheep quietly graze in a biomedically fertilised meadow".
He even hands out medals to sect members he claims have helped to imprison corrupt psychiatrists.
Miscavige then tells us the horrors of the Holocaust "did not begin with a Nazi declaration of war".
He says: "The bureaucracy, the methodology, even the ideology for mass murder, sprang fully-armed from the forehead of German psychiatry."
He goes on to claim that psychiatric euthanasia centres had already claimed 70,000 lives by 1939.
"And that was not the Holocaust," he adds, smugly.
"That was just the dress rehearsal."
Then come yet more statistics, more achievements, more boasting.
Every few minutes the crowd is on its feet, hooting and hollering.
The last item in the four-hour presentation is the sect's new DVD, simply called Scientology. It is thrust upon us by pushy members wanting to make a sale.
But we get out without a copy. Dauntless, dominant, resolute.
And bloody pleased to be going.
Outside the Saint Hill estate is another gathering of people desperate to tell their side of the Scientology story - one littered with claims of abuse, manipulation and terror.
An open conference, titled "The Cult In Your Backyard", it is attended by those who have "escaped" the sect and tried to shine their own light on the mysterious organisation.
They include Steven Jones, 48, from East Grinstead, who left the organisation in 2008.
He claims: "A lot of Scientologists have been through trauma. They prey on weaknesses.
"Scientology promises to make you a better person. To improve your intelligence, your happiness and your memory. I became brainwashed.
"I became very compliant, did what I was told - and handed over money whenever they asked."
Steven says he parted with £80,000 for the sect's self-improvement courses and projects.
He claims: "It starts off with courses for £30 then you end up spending thousands at a time.
"I've been damaged emotionally and I wasted 20 years of my life."
John McGhee, 34, an embalmer from Dublin, says he followed Scientology for three years from 2008, drawn in by, in his words, "the weirdness and the controversy surrounding it".
John says he spent around £18,000 during his time with the sect.
He claims: "At one stage they picked me up from work and drove me to the bank to pick up money... I believe it ruins lives. I want to see it brought down."
Osteopath Vicky Ballard, 65, from Brighton says she was high up in management at Saint Hill, but when she disagreed with certain teachings she alleges the organisation tried to break up her family.
She claims: "Looking back, I realise I was lucky to be chucked out. But at the time it was awful.
"My children were in a Scientology school and they tried to take them away from me."
Samantha Domingo, 45, from Kent, alleges that the church leaders forced her to have an abortion at 24.
She says: "I was so under their control that I did what they wanted.
"I just want to see the Church of Scientology crumble. It is a cancer, rotten to the core. But it's in trouble.
"Tom Cruise is said to be unhappy, John Travolta seems to have taken a step back. I believe their numbers are decreasing and they're worried."
Sect of secrets
Scientology was founded in 1952 by the late L Ron Hubbard, a science fiction writer from the US.
His best-selling book, Dianetics, is a key text for those who follow the faith.
He claimed humans are beings called Thetans, which have lived for trillions of years and are constantly reincarnating.
As well as attempting to explain the power of the mind, it promotes a unique counselling technique Scientologists call "auditing" to enable individuals to deal with their past.
The cult has several high-profile converts who are thought to hand over large sums of money to it.
Hubbard bought Saint Hill Manor in West Sussex as Scientology's British HQ in 1959.
In October 2006 a multi-million pound Scientology centre was opened in London, attended by Tom Cruise, John Travolta and Juliette Lewis.
The church claims to have 123,000 UK followers.
