Davey Lambert, a 48-year-old man from Gateshead, England, died this week after crashing at the Isle of Man Tourist Trophy, an annual motorcycle event here that claimed two more lives on Wednesday. Four competitors died in the races last year, and another was killed the year before that. Those fatalities brought the death toll at the event, known as the TT, to 146 since it was first run in 1907. If one includes fatal accidents occurring during the Manx Grand Prix, the amateur races held later in the summer on the same Snaefell Mountain Course, the figure rises above 250.

For this reason, and others, the TT has few parallels within global sports. The concept of mortality underpins everything here. It gives the race its prestige, opens it to criticism, makes it exhilarating, makes it terrifying. It puts the island on the map.

It is also why, for two weeks each year, this sleepy rock in the middle of the Irish Sea (population 88,000) becomes something like a rollicking festival ground. Organizers convert 37.73 miles of undulating public roads into an enormous, claw-shaped racetrack, and roughly 40,000 visitors, many of them bringing their own motorcycles, join local fans for a week of practices and a week of competition. It all culminates with the Senior TT, which takes place this Friday, a public holiday on the Isle of Man. (Schools are closed for the entire race week.)

Speeds over the four race days routinely exceed 200 miles per hour. Every year, there are crashes. Almost every year, there are deaths.

Deaths by year 6 4 2 0 1911 1930 1960 1990 2016 Deaths by year 6 4 2 0 1911 1930 1960 1990 2016 Deaths by year 6 4 2 0 1911 1930 1960 1990 2016

For riders, the TT — arguably the world’s most dangerous race — represents a supreme challenge. Yet many of the world’s best professionals have never put tire to pavement on the course. They know that the consequences of even a minor mistake can be fatal.

“If Roger Federer misses a shot, he loses a point,” said Richard Quayle, a former TT winner. “If I miss an apex, I lose my life.”

From grandstand to finish line, here’s a tour of the deadly corners, colorful characters and rich history along one lap of the Isle of Man TT course:

GINGER HALL TO RAMSEY This area is one of the riders’ least favorite portions because of the bumpiness of the road and the curves. Bride Andreas Ramsey RAMSEY HAIRPIN The hairpin, a walking-speed turn heading up to the mountain. 25 Jurby Joey’s Glentramman SULBY STRAIGHT In 2015, James Hillier hit 206 miles per hour along this stretch. 20 Sulby Mountain Mile Ballacrye Jump Mountain box VERANDAH Conor Cummins lost control here in 2010; video of the spectacular crash has been viewed millions of times online. Ballaugh BALLAUGH BRIDGE In 2014, a rider named Bob Price died after he lost control going over the humpback Ballaugh Bridge and careened directly into the side of the Raven Pub. Deaths of riders, spectators and officials since 1911 Alpine Mile marker 30 Laxey The Bungalow Rhencullen Snaefell Mountain Course 15 Baldrine Windy Corner KEPPEL GATE Years ago, there was an actual sheep gate here. The first man through on a race day had to open the gate, and the last man had to shut it again. Brake Leg Clypse Course Barregarrow Irish Sea Creg-Ny-Baa 35 Handley's Brandish Onchan Cronk-y-Voddy Straight Signpost Corner 10 GRANDSTAND The big grandstand and the gigantic hand-operated scoreboard across the street are permanent year-round fixtures on the course. Glen Hellen BLACK DUB From Laurel Bank to Glen Hellen, sunlight through the overhanging branches has a strobe effect on the road, making it difficult to see and perceive the course. Douglas Laurel Bank 5 Union Mills Ballagarey St John's Peel Braaid Foxdale Port Soderick Newtown Glen Maye north ISLE OF MAN Dalby 3 Miles Niarbyl Ballasalla Ronague Ballabeg Colby Castletown Scotland Port Erin Course elevation N.Ireland Verandah DETAIL 1,500 feet Ireland Cregneash England 1,000 Cronk-y-Voddy Wales Sulby Bridge 500 0 0 miles 10 20 30 37.7 GINGER HALL TO RAMSEY This area is one of the riders’ least favorite portions because of the bumpiness of the road and the curves. Bride SULBY STRAIGHT In 2015, James Hillier hit 206 miles per hour along this stretch. Ramsey RAMSEY HAIRPIN The hairpin, a walking-speed turn heading up to the mountain. 25 Jurby Joey’s Glentramman 20 Sulby Mountain Mile Ballacrye Jump Mountain box VERANDAH Conor Cummins lost control here in 2010; video of the spectacular crash has been viewed millions of times online. Ballaugh Deaths of riders, spectators and officials since 1911 Alpine Mile marker 30 Laxey The Bungalow Rhencullen Snaefell Mountain Course 15 Baldrine Windy Corner Brake Leg Clypse Course Barregarrow Creg-Ny-Baa Handley's 35 Brandish Onchan Cronk-y-Voddy Straight Signpost Corner 10 GRANDSTAND The big grandstand and the gigantic hand-operated scoreboard across the street are permanent year-round fixtures on the course. Glen Hellen Douglas Laurel Bank 5 Union Mills St John's Ballagarey Peel Braaid Foxdale Newtown Glen Maye ISLE OF MAN Dalby Scotland Niarbyl N.Ireland DETAIL Ballasalla Ronague Ireland England Wales Ballabeg Irish Sea Colby Castletown Port Erin Course elevation north Verandah 1,500 feet Cregneash Cronk-y-Voddy 1,000 Sulby Bridge 500 3 Miles 0 0 miles 10 20 30 37.7 GINGER HALL TO RAMSEY This area is one of the riders’ least favorite portions because of the bumpiness of the road and the curves. Bride SULBY STRAIGHT In 2015, James Hillier hit 206 miles per hour along this stretch. Ramsey 25 Jurby Joey’s Glentramman 20 Sulby Mountain Mile Ballacrye Jump Mountain box Ballaugh Deaths of riders, spectators and officials since 1911 Alpine Mile marker 30 Laxey The Bungalow Rhencullen Snaefell Mountain Course 15 Baldrine Windy Corner Brake Leg Clypse Course Barregarrow Creg-Ny-Baa GRANDSTAND The big grandstand and the gigantic, hand-operated scoreboard across the street are permanent, year-round fixtures on the course. Handley's 35 Brandish Onchan Cronk-y-Voddy Straight Signpost Corner 10 Glen Hellen Douglas Laurel Bank 5 Union Mills St John's Ballagarey Peel Braaid Foxdale Newtown Glen Maye ISLE OF MAN Dalby Niarbyl north Ballasalla Ronague Irish Sea Ballabeg Colby Castletown 3 Miles Port Erin Scotland Course elevation N.Ireland Cregneash DETAIL Verandah Ireland 1,500 feet England Cronk-y-Voddy Wales 1,000 Sulby Bridge 500 0 0 miles 10 20 30 37.7 Scotland N.Ireland DETAIL Ireland England Wales Bride Snaefell Mountain Course Ramsey Jurby 25 Joey’s 20 Sulby Mountain Mile Ballacrye Jump Mountain box Deaths of riders, spectators and officials since 1911 Alpine Mile marker 30 Laxey 15 Windy Corner Brake Leg Creg-Ny-Baa Handley's 35 Onchan 10 Glen Hellen Douglas 5 Peel Ballagarey St John's Port Soderick Foxdale ISLE OF MAN Dalby Niarbyl Ballasalla Ronague Colby Castletown Irish Sea Port Erin Cregneash north 5 Miles Course elevation Verandah 1,500 feet Cronk-y-Voddy 1,000 Sulby Bridge 500 0 0 miles 10 20 30 37.7

Tom Jenkins/Getty Images

Grandstand: Where Skill and Danger Draw a Crowd

The grandstand area represents the TT’s main hive, brimming with energy and anticipation. The race days begin here, swelling with human drama and competitive intrigue and the thrill of possibility.

This was not always the case. In 1976, after a string of high-profile deaths and ensuing criticism, the TT lost its world championship status. For the next 30 years, the event grew stagnant and stumbled along, until many came to believe that the centenary races, in 2007, would be the final ones.

But the TT survived, and for that many thank Paul Phillips, 38, whom many simply know as “the boss of the TT.” In 2006, Phillips left a job in finance, taking a significant pay cut, to accept a government position as the Motorsport Development Manager for the Isle of Man and the difficult task of resuscitating the island’s beloved races.

“I felt, then, and I still feel now, that it’s a public service, really,” he said of his job.

Phillips and his colleagues recruited better riders, negotiated new media contracts and refocused on the safety standards that some felt had become an afterthought. At the same time, they marketed risk alongside skill.

“Before my tenure here, there was an underlying there’s-nothing-to-see-here kind of mentality, and to the wider world, to me, it felt like we came across as a group as kind of bloodthirsty and ignorant,” Phillips said. “Now, all of our marketing is about: ‘This is the most dangerous race in the world. These guys are the gladiators.’ ”

And the crowds, the excitement, and the money have returned.

Guy Martin’s bike exploded during a crash in 2010. Sean Sayers

Ballagarey: More Like “Balla-Scary”

The Mountain Course features several hundred distinct turns, but according to Quayle, Ballagarey Corner — or as he calls it, “Balla-scary” — is its most crucial.

The turn appears early in a rider’s lap, so neither they nor their bikes are properly warmed up. Riders arrive at high speed and exit onto a mouthwatering two-mile straight, meaning precious seconds are at stake. And it is a blind corner, which activates defensive reflexes in even the most seasoned riders.

“Your brain has a natural instinct to be careful, to protect you, to preserve you,” said Quayle, who coaches newcomers every year as a rider liaison. “When you’re rushing into a corner, your brain goes, Slow down, you idiot. Put the brake on. Turn the throttle off.”

Motorcycles enter the corner at close to 180 miles per hour, and things do not always go well. In 2010, Guy Martin, a popular English rider, rammed his Honda CBR1000RR into the stone wall there, creating a terrifyingly cinematic explosion.

Quayle, a bespectacled, eminently excitable 44-year-old Manxman nicknamed Milky, knows every bump and divot on the road. In 2002, he became one of only three people from the island to win a TT. But he stopped racing a year later after a horrific crash of his own.

He still marvels at the absurdity of the course — the roads lined with stone walls, mailboxes, telephone poles and storefronts, the way claustrophobic forest roads swiftly transition into wide-open mountain passages — and it is clear he misses it.

It’s like sex, Quayle said. “We all love it. But the best bit’s the orgasm, isn’t it? And you can’t have that all the time, can you? But here, when you’re riding around here, you’re getting that orgasm all the time.”

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Black Dub: Riding Together, Crashing Together

Even within the motorsports community, sidecar racers are considered a peculiar breed. It takes a special sort of madness, competitors say, to put your life so fully in the guardianship of another racer.

Growing up in England, Ben Birchall always dreamed of being a solo racer, but when he turned 18, he found he had neither the money nor the connections to make it happen. Becoming a sidecar passenger, though, was another story — an easier, if crazier, way to get into the game.

“Drivers always need passengers,” Birchall, 40, said with a chuckle. “You just need some leathers and some will and probably not much brain power and certainly a lot of nerves.”

Sidecar passengers sit crouched on a platform with nothing to secure them except two handgrips. They serve as ballast for their motorcycles, sliding one way, arching their bodies another way, depending on feel and intuition and memory to move their weight around to aid their drivers.

Birchall spent 10 years as a passenger before earning the money to become a driver. When he did, his brother Tom, 10 years his junior, became his first passenger. The two have since become one of the world’s top teams, winning the sidecar world championship in 2009 and notching five TT wins. Their latest came Monday, when they set a new TT sidecar lap record, averaging 117.119 miles an hour.

“It’s a bit like a drug,” Tom Birchall said about riding in a sidecar. “You just keep chasing it. It’s a cliché, isn’t it? But it’s the closest thing I could imagine it to.”

The Birchalls’ motorsport addiction began when they were kids. Their parents, who honeymooned at the TT in 1969, brought their children to the Isle of Man each year. They said it was easy not to let brotherly love get in the way of aggressive racing, but when they crashed at Black Dub three years ago, their fraternal instincts emerged again, each one thinking first about the safety of the other.

“He was shouting for me, and I was shouting for him, as we were both spread across the road,” Tom Birchall said, laughing.

Photographs by Getty Images and National Motor Museum

Ballaugh Bridge: Prepare for Takeoff

Gene McDonnell died near Ballaugh Bridge in 1986 in what even the competition’s official website calls “the most horrific accident ever witnessed at the TT.” It began when a helicopter dispatched to rescue a fallen rider spooked a horse, which bounded over several fences and dashed onto the racecourse — directly into the path of McDonnell, who barreled into the animal at full speed. Both McDonnell and the horse died, and McDonnell’s bike exploded into a ball of flames after crashing into a row of parked cars.

As you see in the pictures above, it's near impossible to clear the bridge without catching some air. But soar too high or too far, and the landing can be deadly.

In 2014, a rider named Bob Price died after he lost control going over the humpback bridge and careened directly into the side of the Raven Pub, a popular establishment just beyond it. Today, there is a wooden plaque, only a few inches long, on the brick wall of the pub. On it are the words, “Rest in Peace Bob.”

Hilary Musson with her Aprilia RS250. Andrew Testa for The New York Times

Hilary Musson: Never Far From the Roar

Hilary Musson remembers getting dressed and riding her motorcycle up the mountain to the 26th milestone, where she was posted as a race marshal one day a decade ago. The next thing she remembers is waking up in a hospital bed. She remembers feeling bewildered when her husband, John, informed her that six weeks had passed since she had opened her eyes. She remembers looking down at her left leg and she remembers it not being there.

“There are a lot of accidents during the races, but not a lot involving spectators, marshals, members of the public,” said Musson, now 70, taking a deep breath as she sat in her dining room. “But it had to be me.”

Musson knew the risks. In 1978, after years of competing in local races, Musson became the second woman to compete in the TT, ending a de facto 16-year ban on female participants. Musson finished 15th, one place behind her husband.

“It was just a huge sense of achievement when I finished it, because people didn’t think I would,” Musson said.

In decades of races, she had only two accidents, and her most serious injury from the two of them had been a bruised wrist. She and her husband moved to the Isle of Man in 2006, only a year before the accident. She never thought she would be hurt years after she stopped competing.

On the day of the crash — June 7, 2007 — a rider charging along the mountain course clipped a pole at high speed and was killed instantly. His motorcycle, now a rogue 400-pound missile, zigzagged back across the pavement and hurtled into a crowd of onlookers. Two spectators were killed, and two marshals, including Musson, were badly injured. When Musson awoke later that summer, she was told she had sustained fractures to her ribs, vertebrae and legs, a burst spleen and a severed femoral artery. Her left leg was amputated above the knee.

The vest she was wearing that morning, which she has kept to this day, has a tire print across the back.

“I still find it difficult to accept it, even now, because it wasn’t my fault,” said Musson, who still volunteers at the races. “I still feel it was a bit cruel, I’d say.”

From her living room, she can hear the motorcycles roaring down the Sulby Straight, one of the fastest stretches of the course. Just inside her front door sits a motorcycle, a glistening Aprilia RS250. She bought it more than 20 years ago.

“John keeps trying to get me to sell it, but I just like to see it there,” she said. “I’ve always said I’d get on a bike again, but longer I leave it, the more difficult it’s getting.”

Joey Dunlop Simon Miles/Getty Images

Joey’s: Honoring the TT’s Greatest

The king of the race remains Joey Dunlop, who won a record 26 events at the TT. His sublime skills are revered today, nearly two decades after his death in a race in Estonia, even though many fans have only ever seen him compete in video clips.

“At certain corners coming through here, if you’re one foot to one side of where you should be, the bike is practically uncontrollable,” said Roy Moore, a longtime radio commentator for the TT. “Joey Dunlop, they reckon if you put a sixpence on the bloody road on a corner he would ride over it every time, because of his memory and because his ability to be in exactly the right gear, pointing in the right direction, was the same every lap he went on.”

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Verandah: YouTube’s Favorite Crash

It took Conor Cummins a few months to watch the video, and as far as he is concerned, he never needs to see it again.

Filmed from above, he appears surging through Verandah, a wavy, four-turn passage on the mountain, at 150 miles an hour. As he leans into a rightward curve, he loses control and his motorcycle slides out from under him, leaving him skimming on his back, as if the pavement were a sheet of ice. With nothing to stop his momentum, he clips the edge of the road and spills off the course, tumbling violently down a steep hillside. His body bounces off the ground, twirls in the air like a can tossed from a speeding car and crash-lands, finally, amid a hail of splintered motorcycle parts hundreds of feet from the spot where he lost control.

Sickening as it is, video of the crash, from 2010, has been viewed millions of times online. The most horrific moment of Cummins’s life endures as a viral video.

“If I had a pound for every time that was watched, I think I’d be a wealthy person,” said Cummins, 30, an Isle of Man native with four podium finishes at the TT. “Is sadistic the word? But something like that is drama, isn’t it? And there’s a percentage of people who like that drama. And yeah, it was a spectacular crash. I can’t lie about that.”

Cummins spent two months in the hospital. Rods, plates and screws were inserted up and down his body to stabilize all the fractures he sustained. The incident left thick scars snarled around his skin and a traumatic memory etched into his mind.

And still, the very next year he was back at the TT, perched on his bike, zooming through Verandah.

Andrew Testa for The New York Times

Creg-Ny-Baa: Take in the View With a Pint

“Little businesses here rely on the TT, and for some, without a doubt, the race alone is what keeps them going all year,” said Steve Christie, 46, who helps run the Creg-Ny-Baa, a famous pub along the course.

Back in the 1960s and 70s, tourists packed the Isle of Man’s hotels and restaurants and shops, and for a few weeks each year, the island feels like its old self. Last fall, the government reported that more than 42,000 people, from more than 40 countries, visited the island during the 2016 TT. They spent an estimated 31.3 million pounds, about $40 million.

Christie said that the Creg does about a third of its yearly business during the annual race weeks. In addition to a lively party, the pub offers a stirring view. Riders descend the mountain from Kate’s Cottage, near the 34th milepost, at 150 miles an hour, pull their motorcycles into right turn at around 80 m.p.h. and then rush into a straight that some riders consider the fastest on the course.

Ian Hutchinson, left, and Michael Dunlop are the favorites in this year’s race. Photographs by Getty Images

The Finish Line: Two Racers Stand Apart

The TT field has grown ever more competitive over the last decade, but at the moment two riders stand apart from the rest: Ian Hutchinson, who won three races last year, and Michael Dunlop, who captured two. That the two men finished last year’s competition engaged in a war of words had only heightened the anticipation for their showdown this year.

“I’m sure they have mutual respect, but they don’t particularly like each other,” said John Watterson, the sports editor for Isle of Man Newspapers. “They will push it. I hope they don’t hurt themselves doing it.”

Hutchinson, 37, of West Yorkshire, England, won the Superbike race on Sunday, improving his TT win total to 15.

Dunlop, 28, from Ballymoney, Northern Ireland, has won 13 races at the TT. He descends from a racing family with a history at once proud and tragic: He is the son of Robert Dunlop (five TT wins) and the nephew of Joey (the most decorated TT racer, with 26 wins), both of whom were killed in racing crashes. Michael Dunlop famously competed in a race only two days after his father’s death in 2008 — and won.

“He’s a maverick,” said Moore, the radio commentator. “He just rides the thing like a lunatic — in control, but sometimes not where he should be. But he’s a hell of a rider.”

Last year, Dunlop set a single lap record, at 16 minutes 53.929 seconds, averaging a blistering 133.962 miles an hour. “You think you know everything, but you can always ride harder and harder and get faster and faster,” Dunlop said.

Andrew Testa for The New York Times

The Crematorium: The TT’s Eerie Neighbor

The ashes of Christine Cowley’s brother Paul were heavier than she expected — more like coarse sand than, say, the ash from a burning cigarette. He had told family members where he wanted his ashes spread if he were to die racing. They never thought they would have to do it.

After the funeral at Douglas Borough Crematorium — located, rather ominously, a few hundred feet from the finish line — Christine Cowley walked out to Quarterbridge Road, the spot where she and Paul had used to watch the races with their father. She and her mother awkwardly scooped his ashes with the cap of a medicine bottle. They kept losing their footing on the soft ground, and soon bits of ash were getting under their fingernails. They began to laugh, which felt strange. But it also felt good.

Paul Cowley was a sidecar passenger, like his dad. He died in 2004, after losing his grip on a practice lap near the ninth milepost. He was 22 years old and engaged to be married. His baby girl, Shauna, was born four months after his funeral.

For two years after his death, Christine Cowley left the island during the races, trying to shelter herself from the memories. Each time, though, she found herself following the results and gossip online. The third year, she stayed, and though it was tough, she enjoyed it, too. The race, she realized, was part of her DNA.