The bell tolls - eight chimes. A fuse is lit and a rocket takes off. The pen doors open and out burst 12 behemoths - six bulls and six steers - working their pace up to a gallop, hooves thundering on the cobbled streets.
On cue, throngs of white-clad runners begin to sprint. They glance back, ready to dodge the charging beasts' piked horns with balletic moves defying a gory demise. Enraptured onlookers cheer on from balconies above.
It's the feast of St Fermin, the famed bull-running festival that engulfs downtown Pamplona every July when revelers from around the globe descend upon the northern Spanish city for nine days of adrenaline.
Some are drawn to the Sanfermines - as the festival is popularly known - by the timeless prose of one of the grandees of 20th-century American literature.
Ernest Hemingway (1899-1961) became besotted with the Sanfermines on his first visit, exactly 100 years ago. The bull-running, the bullfighting local experts - and the hedonistic partying - captivated him so deeply that he returned eight times between 1924 and 1959.
In 1926, he set his debut novel "The Sun Also Rises" partly in Pamplona. Based on his experiences there and among the American and British expat community in Paris, Hemingway quickly established himself with the book as the voice of what became known as the post-World War One "Lost Generation."
In the book, the narrator - Hemingway's alter-ego - chronicles a tale of excess, of constant and in some ways desperate carousing broken only by trips to the bullring to watch the bloody encounters.
"I can't stand it to think my life is going so fast and I'm not really living it," says one character in a famous exchange.
"Nobody ever lives their life all the way up except bull-fighters," replies the narrator.
Bill Hillmann, an English professor from Chicago and expert bull-runner, first read "The Sun Also Rises" while in college when he was 20. When the now 41-year-old turned the last page, he knew two things: He wanted to become a writer, and he would run in front of Pamplona's bulls someday.
Hillmann's first run was in 2005. He's been a fixture ever since.
"I got here and I was just blown away by it. It was everything in the book but times ten, you know. It was bigger. It was wilder. It was crazier," he says.
Over the years, he became friends with Hemingway's grandson John and great-grandson Michael. Being gored twice, in 2014 and 2017, hasn't dampened his enthusiasm.
"I've basically been kind of following Hemingway's ghost around, you know, and I'm a little bit haunted by him," Hillmann says.
For Cheryl Mountcastle, 69, her first encounter with "The Sun Also Rises" was at her New Orleans high school. For the past 24 years, she has rented the same apartment in Pamplona for the festival with her family. She says the novel's emphasis on drinking omits another side of the festival - such as sharing food and dancing in the street.
Leontxi Arrieta is one of the few remaining Pamplonians who met Hemingway in the flesh. The 91-year-old tells Reuters her family hosted the writer and his fourth wife, Mary Welsh, in their last visit to Sanfermines in 1959, two years before his death.
What has changed and what hasn’t
There's a recurring debate among Pamplona's residents: Is the city's overcrowding during Sanfermines Hemingway's fault? Did he misrepresent its essence in his writings? Has it been a victim of the novel's success?
Last year, 1.7 million people attended, leaving 1,200 tons of broken glass and assorted waste behind. A coveted spot on a balcony with a prime view of the bull-running can easily fetch 200 euros ($220) per person.
Pamplona native Miguel Izu, 63, who among several books on Sanfermines has penned one about the festival's links to Hemingway, believes the novelist's influence on its popularity has been exaggerated.
"It's true that he's contributed to making Sanfermines famous and bringing people here, but before Hemingway, tourists were already coming, especially from France," Izu explains.
Hemingway was unknown during his 1923 trip, he says, and only became a world-renowned figure after earning the Nobel Prize in 1954.
Izu acknowledges the city was still exploiting Hemingway's image to promote itself, "either deliberately or unconsciously". But the reverse also applies: "We made him into a sort of Sanfermines icon - you can't talk about them without mentioning Hemingway."
But not every foreigner at the festival has been lured by the author, especially since the rise of social media. Australian William Kappal, 23, and his friends were instead attracted by YouTube videos showcasing the exhilarating danger of the bull-running coupled with plenty of roistering.
Asked if they had ever heard of Hemingway, Kappal chuckles.
"Nah. Should we look him up?"
Many things have changed since 1923 - the familiar white outfits decked with red scarves and waistbands worn by runners, for instance, only came into fashion after 1931 - and northern Spain has transitioned from an agrarian to an industrialized society. But the essence of the festival remains, Izu says.
Cafes featured in the book such as the Iruña still welcome revelers. Visitors still party, and pray, and seek a space in the crowded streets to get a view of the bulls without risk of being gored by those devilish horns.
Says Izu: "I think that if (Hemingway) came back to life ... he would look around and say: 'Some things are strange, but well, it's basically the same old Sanfermines.'"
