Six months ago Ahmet Celik, a Turkish kebab shop owner who lived in the Green Lanes area of north London, disappeared from his home.
He left only with the clothes on his back and fled from loan sharks linked to the Tottenham Boys and the Bombacilar, two of the capital's most ruthless Turkish heroin and racketeering gangs.
His departure caused great disquiet, not least because the genial 36-year-old was well liked among his friends, who knew him as a scrupulously honest, hard-working man, but also because, to protect himself and others, he had not even told his 32-year-old Irish wife that he was going.
This week Ahmet returned to London, albeit just for a few hours. Sweating, fearful and furtively looking over his shoulder, he meets me at a secret rendezvous.
After checking we haven't been followed, he begins: "I have lost everything: my business, my wife, my life as I knew it. My life is hell. I am stressed, afraid to go out, I think many times about suicide.
"Already, three men have been shot dead by these gangs this year. I can be next. In Turkish we say, 'My head is under my arm.' It means I am dead man walking."
What started as a seemingly harmless £13,000 bridging loan from a friend of a friend 18 months ago drew Ahmet into a frightening world of extortion and intimidation.
The lender, it turned out, was a loan shark connected to the Turkish mob, thought to control 90 per cent of heroin smuggled into Britain. He charged Ahmet a prohibitive 240 per cent interest rate and unilaterally penalised him by doubling his debt if he was even a day late.
Desperate to relieve the pressure and repay this loan shark, Ahmet, who came to London from Turkey in 1991, borrowed from another loan shark connected to a rival Turkish gang, the Bombacilar ("the bombers"), but it only made things worse.
Over the course of a year he paid £63,000 on the original £13,000 owed, he says, even selling his business in a frantic attempt to pay off the sharks, but they kept on extorting more money and refused to leave him alone.
He was beaten up and went to the police but they were unable to afford him the protection he needed, he says, and so, having been given a final deadline, he kissed his wife goodbye - he was "too ashamed" to tell her he had lost everything - and disappeared into the night.
The story of why Ahmet (whose name has been changed for his protection) fled for his life illuminates a wider tragedy besetting the Turkish-speaking community in north London.
So far this year, a ferocious turf war between the Tottenham Boys and the Bombacilar (also known as the Hackney Boys) - both gangs are Turks of Kurdish ethnicity - has led to 35 major incidents, including three fatal shootings, 20 high-profile shootings and a dozen stabbings and arson attacks.
This explosion of violence led to the drastic police decision to deploy officers armed with semi-automatic sub-machineguns on routine patrols on the streets of London for the first time, a decision that provoked a hail of criticism before being hastily reversed by Commissioner Sir Paul Stephenson. (Almost all the Turkish Kurds have come to the UK as refugees in the past 15 years, whereas other Turks in the community, like the Turkish Cypriots, are well established, having been here since the late 1950s when Cyprus was part of the British Empire.)
Beneath the escalating violence, which police say is the cause of the 17 per cent rise in gun crime on London's streets this year, is a vicious battle for control of the capital's heroin trade which, despite the efforts of our armed forces against the Taliban in Helmand Province, continues to flow in from Afghanistan.
It began on 28 January as a minor fracas between two mid-level members of the rival gangs in the Manor Club pool hall and then spiralled out of control.
In March, Ahmet Paytak, 50, "an innocent" was gunned down in the doorway of his Euro Wine and Food grocery store in Holloway as he locked up, killed in a case of mistaken identity.
But his death only led to an escalation in violence, with serious shootings every week, mostly within a narrow two-mile band between the Green Lanes area of Haringey and Clapton in Hackney.
In early October, the turf war claimed its second fatality of the year when Oktay Erbasli, 23, a well-known member of the Tottenham Boys, was killed by a hitman linked to the Bombacilar gang.
Within 72 hours, the Tottenham Boys struck back, executing Cem Duzgun, 21, as he played snooker in a Clapton social club. So far, nobody has been charged over these three murders.
In addition to the shootings, local Turkish shopkeepers have long bitterly complained about the endemic extortion and loan-sharking they are forced to endure at the hands of these racketeering gangs.
According to Ahmet, the Tottenham Boys are about 200-strong and aged mostly 15 to 25 with the leaders in their thirties, although the police dispute this and say there are fewer than 100 of them.
One north London Kurdish community leader says: "The extortion has been going on for years. We believe their takings from protection rackets run into millions and are as high as those from the importation and trade of heroin and cannabis. Something must be done but people are too terrified to come forward to the police because for so long the police have not intervened."
The fear is such that even this community leader, who speaks to me on the record, later calls in a panic to ask for his quote to be anonymous.
A property on the Seven Sisters Road has just been burnt down as part of the tit-for-tat war and he fears his community centre could be attacked if he speaks out.
This month the four Metropolitan Police borough commanders of Haringey, Enfield, Islington and Hackney met community leaders in a summit at Hackney Town Hall to share intelligence and reassure them that they are taking their concerns seriously.
The police told them a number of arrests were imminent and that they had information that a major shooting was planned at a wedding in Haringey at the weekend. (A highly visible police presence ensured this shooting was averted.)
One of those present, David Lammy, MP for Tottenham, tells the Standard: "I am worried about what appears to be increasingly powerful international criminal gangs operating in parts of north London.
"Their racketeering, loan-sharking and heroin war is stigmatising what is otherwise a law-abiding community and creating what one Kurdish leader has called a 'survival of the fittest world'.
"What these Londoners need is proper policing. I'm not saying it's easy, but we currently have a situation where some of my constituents are scared for their lives and unable to feel confident that the police will protect them.
"The police need people to come forward if they are to address the serious organised crime that lies behind the shootings, but they also need to deepen their community links and reassure people that it is safe to come forward."
Ironically, police believe the reason behind the surge in shootings is a power vacuum created in the wake of an operation three years ago that took out the leaders of Turkish organised crime.
The jailing for 22 years of Abdullah Baybasin, 48, whose clan controlled a £10billion heroin empire and most of the heroin smuggled into Britain with ruthless efficiency, has given way to something "much more chaotic", says Steve Kavanagh, Metropolitan Police Area Commander for north London.
"These younger groups are not nearly as organised as the Baybasin network and their allegiances are weak, creating a much more volatile situation and leading to levels of violence that are shocking," says Kavanagh.
"We are putting lots of extra resources into the area - including Trident officers, [armed] Territorial Support Group police, dog patrols and other operations I can't discuss - to take back control of the streets."
Indeed, last Friday, three Turkish men living in Enfield - aged 26, 28 and 38 - were arrested and charged at Enfield Magistrates' Court for conspiracy and drug offences as part of the ongoing operation into Turkish criminality.
But Kavanagh admits there are no quick fixes and that it will take more than a few arrests to solve the deeper organised crime issues.
"There is a high level of fear in the community, with innocent people being shot and honest shopkeepers being bullied and extorted.
"The more we reassure people that we can protect them - and we most certainly can - the more they will feel confident to come forward so we can do our job."
But Ahmet's experience is not reassuring. "In April I went to a police station in east London because I'd been given two weeks to pay by loan sharks who had threatened to break my bones and then bury me in their basement.
"The police said I had three options: pay the money, disappear or take the loan sharks to court. I said I wanted to go to court, but I had no documents or evidence that our loan even existed. I asked to be placed under witness protection, but the police couldn't guarantee my safety."
But what finally prompted Ahmet to flee was when he stood up to the Turkish gangsters by brazenly saying he had gone to the police. "The loan shark looked at me and laughed like a hyena. He grabbed me in a headlock and told me, 'Did you see my picture on the wall with my name on top? They know all about me, but they can't do nothing because nobody is stupid enough to stand witness.'"
Ahmet looks me in the eye. "That's when I realised: Green Lanes might look like London, but in reality it exists in a parallel universe ruled by gangs where the law does not apply. That's when I decided to disappear."