This is the story of the man who tried to kill the previous Pope in 1981 and how in doing so he unwittingly helped create one of the great religious beliefs of our modern age.
It is the belief in a global network of terror - and the conviction among its believers that anyone who questions it is a heretic.
It begins with a very brave, but also very obsessive, Lieutenant Colonel in Vietnam called Alexander Haig. Here he is talking as his troops bulldoze and flatten a Vietnamese village.
He perfectly expresses the American military's famous explanation - "It became necessary to destroy the village in order to save it."
Haig's career then took off - and in 1969 he was made Henry Kissinger's assistant.
Almost immediately he became involved in the secret bombing of Cambodia.
The American military was convinced there was a giant secret bunker hidden in Cambodia from which the North Vietnamese were directing their attacks. The bombing, followed by an invasion, was going to destroy it.
But the bunker was never found. It seems never to have existed.
But it became a vision that was going to possess Haig, and others, in the years to come. That somewhere there is a hidden central control where the enemies of America are co-ordinating their attacks.
They know this secret place exists. Even if there is no real evidence.
And you can do bad things and cut corners in order to prove it exists.
Here is some footage - first from the invasion with an American Major from the US Cavalry convinced they are going to find the bunker. Then William Shawcross describing the illegal things that Haig was involved in. Followed by a report of what they did find.
Haig then became President Nixon's chief of staff during Nixon's final - paranoid - days.
After that he became the commander of NATO in Europe. And as his power grew so did his vision of the hidden threat. In 1979 Haig made a speech about what he called the new "global disease of terrorism" which he was convinced the Soviet Union was behind.
Up to this point the terrorists in Europe and Latin America and elsewhere had been seen as disparate groups. They might know each other - but they were separate movements driven by their own weird interpretations of leftist or rightist theory.
Haig was saying - no, they are all part of something bigger. Here is part of his speech.
Then - a month later - a group of terrorists tried to kill Alexander Haig.
The German group, the Red Army Faction, hid a bomb under a bridge in Belgium and detonated it as Haig's motorcade went over it. But they mistimed it by a few seconds.
For Haig it was evidence of an international plot to get him.
By now Haig was not alone.
In July 1979 a conference was held in Jerusalem to discuss the phenomenon of "International Terrorism". It was organised by a young Benjamin Netanyahu at the Jonathan Institute, named after his brother who had been killed by terrorists at Entebbe.
All sorts of people were there, including George Bush Snr, many Neoconservatives who would become influential in Bush Jnr's adminsitration, and Prime Minister Begin.
But the agenda of the conference was shaped by a new breed of what would become known as "terror experts". And all of them were convinced by the new theory that the KGB were running almost all terrorism around the world.
They were also great, and sometimes very weird,characters.
One was an Australian journalist and novelist who wrote for the British Economist called Robert Moss.
Moss was one of the earliest promoters of the idea of hidden Soviet control. And in 1976 he helped write the speech for Mrs Thatcher that led the Soviets to call her the Iron Lady.
Later - in the mid 80s - Moss decided he had found a route to perceiving higher truths in the world. Truths hidden from ordinary mundane consciousness.
Through his dreams.
He developed a system he called Active Dreaming. You can find his theory here.
"When we act to bring the energy and imagery of dreams into physical reality, we become poets of consciousness and infuse our world with magic. Deep into multidimensional reality"
Another "terror expert" was a French historian called Annie Kriegel.
She had been a hardline Stalinist in the French Communist Party, but had turned violently against the Soviet Union.
Kriegel was convinced that all the terrorist acts in the Middle East were being co-ordinated from Moscow. This was music to the ears of Benjamin Netanyahu and the Israeli leaders who were seeking further US support.
In 1982 Kriegel wrote a book that said that the massacres in the Sabra-Chatila camps were organised by the Soviets and carried out by German terrorists under KGB control.
But perhaps the most important expert was another ex-communist. An American called Claire Sterling.
Sterling was a journalist who lived in Italy. She took all the "evidence" of Soviet control that was produced a the conference and bundled it up together into a book called The Terror Network.
It had a dramatic thesis.
It said that there was a "Global Terror Network" underneath the surface of most Western societies and the Middle East.
That all of them - the Red Brigades, Baader-Meinhof gang, Provisional IRA, South Moluccans, Japanese Red Army, Iranian terrorists, Turkish People's Liberation Army, Spain's ETA, Popular Front for the Liberation of Palestine and Fatah, the military arm of the Palestine Liberation Organization were all part of a grand Soviet scheme.
The aim of the scheme was to force the police in a Western democracies to crack down on individual freedoms. Then a repressive police state would emerge and breed resentment - making the masses ripe for Communist revolution.
One of Sterling's closest friends in Italy was a young American academic called Michael Ledeen. He was fascinated by the theory.
And then early in 1981 he became a special assistant to the new US Secretary of State in the first Reagan administration.
Who was General Alexander Haig.
Haig read The Terror Network and immediately bought Sterling's theory - because it proved what he instinctively knew about the Soviet threat.
And few days later Haig went to Congress and publicly accused Moscow of "training, funding, and equipping" international terrorists. He announced that "international counterterrorism will take the place of human rights."
William Casey, the new head of the CIA also read and believed Sterling's book.
The only problem was the no-one else took it seriously.
Many of those running the Reagan administration knew that the Soviet Union was supporting and arming liberation movements in the developing world, but they didn't believe in the Global Terror Network.
Casey met with his CIA analysts. He told them that the book - The Terror Network - "has told me more than you bastards whom I pay $50,000 a year."
His analysts then patiently explained to him that much of Claire Sterling's evidence was composed of Black Propaganda they themselves had invented and spread around Europe to discredit to Soviets.
Even Reagan - for all his anti-communism - didn't take it seriously.
But then - on 13th of May 1981 - Mehmet Ali Agca tried to kill the Pope in Rome.
Agca was a member of an extreme right wing Turkish group called the Grey Wolves. But at first Agca said he had done it on his own - it was neither right or left, he said. He was tried and put in prison.
But then in May 1982 Agca suddenly changed his story.
But he didn't say he had done it as a member of the extreme right. Instead he insisted he had been part of a communist conspiracy to kill the Pope that had been organised by the Bulgarian secret service - and was being controlled behind that by Moscow.
Here is a bit of Agca shouting to the Italian press as he was taken from prison for more questioning. Telling them that he was part of a KGB plot.
Claire Sterling seized on this and went into action. She talked to lots of "intelligence informants" in Italy and the rest of Europe and wrote an article for Readers Digest. It caused a worldwide sensation.
Sterling said that Agca showed the incredible spider's web that Moscow had created to control terrorism throughout the world. It had been built in such a way that it was normally impossible to see the links. But, like a flash of lightning on a dark night, Agca had shown how web really worked.
In his case, the KGB controlled the Bulgarian Secret service, and they in turn controlled the Turkish criminal mafia.
The Bulgarians had told the Mafia to find someone who could never be suspected of being linked to Moscow, bring him to Rome and tell him to shoot the Pope.
He would be interpreted as a Muslim fanatic, while Moscow would be rid of a Polish Pope who was a supporting the Solidarity movement in Poland.
Claire Sterling became a media celebrity. She appeared on TV across America and the world. Here she is on Nationwide in December 1982 putting forward her theory.
Sterling's theory caused consternation in the Reagan administration, and especially in the CIA.
Almost all CIA officers and analysts were united in a belief that what Sterling was saying was rubbish. They produced an internal report saying there was no evidence linking the KGB to the assassination attempt.
But the head of the CIA, William Casey, was convinced by Sterling.
A senior CIA analyst called Melvin Goodman testified in 1991 to a Senate Committee as to what Casey then did.
He forced CIA officers to alter the report's main judgements and to "stack the deck" in favour of KGB complicity. The sections of the report that expressed doubts and had counter arguments were erased.
The altered report was then sent to the White House. And it became one of the underpinnings of President Reagan's increasingly simplified view of the world - that there was an interconnected network of terror in the world.
Although a new puppet master had also appeared, along with the Soviet Union - Iran.
Meanwhile the Pope now travelled the world in a protected, high-defence series of pope-mobiles.
Here is a report from the Pope's visit to Britain in 1982 about how British Leyland have built both the standard model and super-giant protected version - under guidance from terror advisers.
I very much like Kevin Beadle from British Leyland who is interviewed. He is so deadpan - the reporter must have hated him.
But then it all went wrong for the global terror theory.
Agca was put on trial again, but this time with seven others. They were accused of being part of a Soviet backed conspiracy to kill the pope.
But the problem was that the prosecution seemed unable to produce any real evidence.
And then Agca himself started talking in court. And it became increasingly clear that he was disturbed and delusional. At one point he announced to the court that he was Jesus Christ and the world was about to end.
Some journalists tried to keep the faith and said that the mad ramblings and his lies were part of a cunning plan. But others began to report the case as a growing fiasco.
Here is BBC news report from the courtroom which gives you a really good idea of how Agca really was out where the buses don't run.
In the end all of the accused were acquitted because there was absolutely no evidence against them.
People went back and looked at Claire Sterling's writings. They pointed out how she also seemed to have no real facts. There were lots of footnotes and references. But when you analysed them they were mostly from secondary "terror experts" who had relied, as she had, on the same Western intelligence sources.
What this meant was that she was citing the same intelligence sources, directly and indirectly, under different names. This then produces a cumulative effect on the unsuspecting reader through a kind of echo chamber.
It was the beginning of the fundamental problem with much of today's "terror industry". They quote each other to produce an illusory breadth of research - when in fact they are often being manipulated by a few intelligence sources with facts they have no ability to check.
And at the same time another media phenomenon rose up.
The terror drama-doc.
At the very time that the Agca-Soviet theory crumbled, the BBC made a film for their "Sunday Premiere" slot called "The Most Dangerous Man in the World".
Here are some extracts. It stars Martin Shaw as a very evil member of the Turkish Mafia.
I've put some captions in explaining how the extracts fit into the story.
I love the bit where some Marxist students try to turn Agca by telling him they can offer "experimental theatre, Brecht and girls".
And there is also great moment where Agca goes to the secret traing camp in Syria where all the world's terrorists come to be trained. And he tells his friend:
"These cats are dealers who deal in rare and expensive violence. The pure stuff"
What Agca had helped create was a powerful modern myth.
It is the idea that underneath all the chaotic violence that marks the modern world there are hidden patterns. Networks of terror that are orchestrated by America's deadly enemies.
This myth reappeared after September 11th 2001. It then fell away again after the debacle in Iraq.
But now it is re-emerging yet again with Iran. And one of the leading promoters is Michael Ledeen. He was Claire Sterling's friend in Italy who did so much to promote the idea in the early years of the Reagan administration.
In his latest book, Accomplice To Evil, Ledeen claims that now Iran is the key lynchpin of a Global Terrorist Network which is engaged in a war against the West.
The reason that no-one can see this network he says is that the mullahs are brilliant at covering their tracks.
At the front of the book he quotes Baudelaire - "The loveliest trick of the Devil is to persuade you he does not exist."
Ledeen is a fascinating man. In the 1970s he wrote a great book about the Italian poet and revolutionary politician, Gabriele D'Annunzio
In 1919, in the chaos at the end of the Great War, D'Annunzio took over the city of Fiume. He was joined by a strange mixture of Futurist artists and revolutionaries from both left and right.
D'Annunzio tried to create a new kind of society in Fiume. He mixed politics with modern art and old religious myths to try and create a heightened awareness among the masses. His aim was to give them a vision of a new kind of world.
The experiment at Fiume has often been portrayed as the beginning of Italian fascism. But Ledeen makes a powerful case that it was far more than that.
What D'Annunzio invented, Ledeen says, is the shape of all modern mass politics. He created melodramatic, theatrical settings to manipulate the masses and so radicalise them.
Behind this was D'Annunzio's belief that there was a hidden, higher reality in the world which the old elites and cowardly politicians prevented ordinary people from seeing.
As Ledeen puts it about D'Annunzio:
"The forces he had awakened (at Fiume) constituted a kind of 'Superworld'. Those, in contrast, that opposed them were an 'Underworld'. It was a poetic vision. It was not fascist or leftist. It was a new way of doing politics.
D' Annunzio's style was the politics of mass manipulation, the politics of myth and symbol which have become the norm in the modern world."
The problem with mass politics today is that we increasingly have no idea what is myth and theatre, and what is really true. And I'm not convinced that Michael Ledeen does either.
In the 1920s D' Annunzio built himself a beautiful garden on the shores of Lake Garda. It expresses his belief that you can shape the world to be what you want it to be. In the midst of it is a real navy cruiser which he hauled up the hillside and embedded in the rocks.
And above it all is a giant mausoleum in which D'Annunzio and some of those who accompanied him in Fiume are buried together.
The whole place is a memorial to D'Annunzio's 'Superworld'.
Here is some footage I took of the Garden. Followed by some old archive of D'Annunzio and his followers in the revolutionary world of Fiume.
Plus some video of the 'Superworld' that the American neoconservatives tried to create nearly a hundred years later.