After three long years, an unmistakable roar is again reverberating down Bray Hill in Douglas before echoing through the quaint towns, villages and valleys of the spectacular Isle of Man countryside.

It is a noise which grows louder as the hedge-side crowds strain their necks for a better view and fix their eyes down the road. And then, within a scarcely believable split-second and a booming VRROOOMM, another bike is gone.

What Murray Walker called “the finest motor-sport event in the world” - the Isle of Man TT - is back and a community of devotees, of which some have been making the pilgrimage for longer than the Queen’s 70-year reign, are immersed in their favourite two weeks of the year.

From the lone elderly man making his way off the ferry on a mobility scooter with a suitcase in the basket to stag and hen parties who are also limbering up for evening acts that include Jessie J, Primal Scream, Madness and Sister Bliss, every segment of society is represented.

But there can be no doubting the stars.

Racing started over the Jubilee weekend when a group of the world's bravest - some would say most reckless - sportspeople reached speeds of more than 200mph along 37.73 miles and 264 corners of open roads.

Tragedy has again struck this year, with five deaths across nine days. But as ever, the show goes on.

Descriptions vary, but most agree that the TT could never happen anywhere but this 85,000-strong self-governing island nation:

“You ride around thinking: ‘We should be in jail’.” - John McGuinness.

“You can’t take any drugs in the world that gives you this.” - Gary Johnson.

“It’s like being sat on an exocet missile.” - Milky Quayle.

“An expression of humanity.” - Dr Gareth Davies.

“A suicide mission.” - Barry Sheene.

Since racing began in 1907 until this year's deaths, the circuit has claimed the lives of 261 people. It has also spawned a thousand legends and, after two cancelled years, many of the modern-day greats are again competing.

There’s McGuinness, a 50-year-old winner of 23 TTs, who has raced long enough to have shared a podium with his iconic hero - the record-breaking 26-times winner Joey Dunlop.

McGuinness has lost some of his closest friends on the course, including Mick Lofthouse on his debut year in 1996 when his accommodation consisted of a Leyland van with “half a kitchen”. He was in two minds about continuing following Lofthouse’s death but a chat with his mate’s grieving father was enough. “He was, ‘Bloody get on with it John’,” recalls McGuinness. “I love the place - the TT is all I think about.”

A man without airs or graces, McGuinness holds folk hero status among his legion of TT fans and had a one-word answer last week when he was asked to sum up F1’s Monaco Grand Prix. “Easy,” he said. His brother Kurt has promised to organise a ‘streakathon’ down the Douglas promenade if McGuinness returns to the podium, let alone wins one of the six main solo races over the next week.

Also competing is Michael Dunlop, nephew of Joey, son of Robert and brother of William. Michael lost all three of those close family members to racing accidents outside the Isle of Man but he still rides on and, at the age of just 33, has already amassed 19 TT wins.

And then there is Peter Hickman, the winner of five TT races who became the fastest ever man around the island in 2018 when he completed a lap in 16mins 42.7 secs at an average speed of 135.452mph. To put that in context, it typically takes 55 minutes to drive the circuit in a car and the best riders in next month’s World Superbike Championships at Donnington will do well to average 100mph.

“I have shown World and European champions around and the main thing they say is the same: ‘It’s so f---ing fast,” says Quayle, the only Manxman to win a TT this century. “The first seven to eight miles through town to Ballacraine takes 25 minutes in a car. They are there in three minutes. Mental. Setting off is a bit like when Captain Sulu presses the button in Star Trek. Whoooshh! I can close my eyes now and still remember that feeling.”

Hickman’s father also raced motorbikes - he spent between 1979 and 1981 in hospital following one crash - but was unable to steer his son away.

“He didn’t want that kind of life for me,” says Hickman. “It’s a dangerous sport, there’s not a lot of money, but it’s either in your blood or not.

“He pushed me into football, cricket, golf, darts. My answer was to buy my own bike when I was 12, and hide it around the back of the house. The rest is history.”

Hickman also races in the British Superbike Championship but says that the TT is incomparable. “You race through villages, woodland, over a mountain, big open areas, tight twisty bits, unbelievably fast bits. I’ve done extreme sports but I cannot find anything that comes even close.” The buzz, says Hickman, lasts for days.

But how does he rationalise the dangers? “Life is dangerous regardless of what you are doing. I’m not worried about the ‘what ifs’. I don't want to get to 100 and have never done anything.

“Everybody probably thinks we take our brains out to go fast. That’s not the case. The people who are good think a lot. It’s calculated risk.”

Assessing a new rider’s technical capabilities and character is now one of Quayle’s jobs as rider liaison officer.

A car mechanic by trade, Quayle retired in 2003 after promising his wife that he would walk away from the sport once they had children. He punctured both lungs and lost his spleen following a spectacular crash at Ballaspur that year which has been watched almost four million times on YouTube.

Alarm bells now ring if Quayle meets a prospective rider who “says they want to be rich, famous and meet loads of girls”. He adds: “We have refused people because their head isn’t in the right place. It’s not how big your cheque book is - it’s, ‘how big are your balls?’ We all do it for the passion of the place. You get so much gratification. The person who finishes last looks like they have won when they get off.

“Short-track racing is like heavy-metal - hard on the brakes, hard on the throttle, raaa, raaa, raaa, all the way around. On the TT, it's like Mozart, apex to apex. I struggle a bit now sometimes - when you have done the ultimate what do you do?”

This year's event was an especially difficult day for Leanne Harper. It was exactly four years since her partner, Dan Kneen, a plumber who was also born and brought up on the island, died instantly at Churchtown after his bike hit a tree and burst into flames.

Kneen’s inquest heard that he was travelling between 180mph and 190mph as his bike “slid away from under him”. He died “doing what he loved”, said the coroner John Needham, a fact of considerable comfort to the family he has left.

“What happened was horrendous but I know Dan was enjoying himself,” says Leanne. “You can deal with it a bit better knowing that. Dan always dreamt of racing in the TT. He lived and breathed it. To get on the podium, and ride against legends … he was like a kid at Christmas.” Leanne then recalls Kneen’s reaction to coming in from one TT ride with a dent in his metal body protector. “I said, ‘what have you done!?’ He was ‘Oh, I just overshot it a little bit and nudged the wall. It was like nothing to them’.

“With the experiences he had and the euphoria he felt, that feeling of being on the edge Dan lived way more than the average 30-year-old. They know the risks, but the passion and joy overcomes that. If he was to have the same experiences again, knowing the outcome, he would probably have still raced the TT. A lot of people don't chase after their dreams. I was just so proud of him.”

A foundation has been created in Kneen’s honour and, among other good causes, fundraising has gone towards equipping the medical team with additional stretchers. Leanne is also among the event volunteers.

“It’s obviously a bit raw but it’s actually really nice to have the TT back,” she says. “The Isle of Man gets a different energy - it starts to buzz. It is a very family-orientated event. You are only getting a decent wage when you hit the podium. We were literally just a family team at the start. People come here and their mechanics are their parents or friends. They do it out of pure love and passion.”

Kneen’s accident was not the only tragedy on May 30, 2018. The race was red flagged and another rider, Steve Mercer, says that he was told to turn around and return to the pits before being hit by an official course car coming the other way.

He was airlifted to hospital, where he remained for five months with a broken back, collapsed lung and fractured larynx. Mercer has said that he would still like to return one day to the TT and movingly posted a Twitter video last month of him again learning to walk. “Still trying, still can’t walk, #keepbelieving,” he wrote. It prompted a reply, among others, from McGuinness: “Keep going mate - you got this.”

The past three years have been used to review every aspect of the event and, according to business development manager Paul Phillips, this will be the most changed TT in history. The visitor influx is again expected to approach 50,000, helping to add around £30 million to the Isle of Man’s economy. Qualifying and races are being streamed live for the first time and there are nightly highlights on ITV.

Like the Tour de France, one of the most striking aspects of the coverage is the sheer beauty of the surroundings. With free access to the paddock and an abundance of salt-of-the-earth personalities, Phillips believes that it is the world’s most accessible major sports event. “It’s a blue-collar sport which pulls in maverick-type characters with a different view of risk - I think our protagonists are the most interesting of any sport,” he says.

There has also been a root-and-branch focus on safety and, while there are very obvious limits on what can be mitigated on a circuit lined with trees, houses, walls and even a 2,000 foot mountain, the mantra is to proactively “eliminate avoidable risk”. Changes include a reduction by 10 this year in rider numbers to 50 or 60, depending on the race, so that backmarkers are more unlikely to be lapped. Qualifying this week was no longer in pairs. There is an electronic red flag system, GPS tracking, a new medical center, added investment in training the 90 marshals, sports science research into factors like how hydration impacts performance and an insistence on the highest standard of protective clothing.

The ongoing counter is of course the increased speed of the bikes and, in the 10 editions before Covid, there were 19 fatalities across the racing fortnight.

“I’m as confident as we can be that this will make a significant difference when we look at it over a prolonged period,” says Phillips.

One key part of the response unit is the three air ambulances which, according to chief medical officer Dr Gareth Davies, can collectively “bring the hospital” to any injured rider within minutes. There are more than 30 doctors and paramedics around the course, whose routine involves pre-race simulation exercises with dummy riders in preparation for what could follow. Staffing at the main Noble’s Hospital has also been increased.

Dr Davies led the accident response for the London Air Ambulance service and was acclaimed for his work on the 7/7 bomings. Having got to know many of the TT riders personally and seen up close the devastating potential consequences, his view of the safety debate is strikingly libertarian and he urges similar focus on preventable accidents in wider society.

“Mountain climbing, extreme sports, going into space… all of those things are dangerous but what they all show to us is a celebration of the human race, what people can do and what they want to do,” he says. “People who love the TT, do so on the basis of celebrating humanity. The riders are incredible but the people around them are incredible as well. The TT is not just an event - it means a lot more ”

The documentary ‘TT3D: Closer To The Edge’ helped make Guy Martin perhaps the best known of the recent generation, even if he retired as the greatest never to win a TT following 17 podium finishes. He would also deliver short shrift for those who advocate a ban. “Get it wrong around here and nine times out of 10 you are dead - that’s the buzz,” he says. “There are not many things left in life where you can do that. Nothing comes close. People might say we have got a death wish but what do they do? Leave us to it. Go and mow your grass on a Sunday morning. We’re not doing anyone any harm … besides ourselves.”

And therein lies the crux. The most tragically affected are often the most vehement supporters.

They might share a potentially fatal attraction but, at its core, the Isle of Man TT is ultimately not about death. It is about living - despite the often terrifyingly fine line between the two.