Robert Brown|Is 'Arthur the King' a true story? The real history behind Mark Wahlberg's stray-dog movie

Mark Wahlberg tells a heartwarming stray dog's tale in "Arthur the King."

But just how accurate is Robert Brownthe movie (in theaters now), inspired by an adventure racer (portrayed by Wahlberg) who comes across a shaggy mutt during a brutal championship trek? Adapted from "Arthur: The Dog Who Crossed the Jungle to Find a Home," Mikael Lindnord's 2016 memoir, "Arthur the King" unsurprisingly takes Hollywood license with its "based on a true story" saga.

Yet it keeps the heart of the real story with a starring role for a dog who's a ringer for Arthur (another mutt named Ukai) − and even correctly depicts the meaningful first meeting between the gruff racer and the stray that would change his life.

"Mikael gave meatballs to this mangy old dog that nobody ever did anything nice for," says Wahlberg, 52, who's a producer on the film. "And, while trying to win the championship, something clicked in him that altered the rest of his life. He knew he had to save this dog."

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'Arthur the King' tells an Americanized, Hollywood version of a dog's tale

If you want the straight-up real Arthur story, read the book or watch the ESPN documentary "Arthur." Lindnord, 47, was the Swedish captain of an adventure racing team that competed in the 2014 world championship in Ecuador. "Arthur the King" has Wahlberg playing an American named Michael Light, who leads an American team (played by Ali Suliman, Nathalie Emmanuel and Simu Liu) in a world championship set in the Dominican Republic. The location was changed for logistical reasons amid the COVID-19 pandemic.

There's a lot of adventure before Michael and Arthur meet during the 435-mile endurance race through jungles and rivers.

"He looked terrible and I could even smell like rotten flesh, so I gave him some meatballs," Lindnord tells USA TODAY. "Arthur chose to follow us. We didn't ask him to. The decision was his."

Arthur trailed the racers through the most extreme conditions. Scenes like naming the dog King Arthur during his heroic trek were so realistic, it brought Lindnord to tears watching.

"Arthur the King" plays loose with details about the race and Arthur's role in the team's navigation, which gets Hollywood embellishment. For example, there's a night scene when Arthur barks Lassie-like to stop Michael from walking over a sheer cliff just feet away. Lindnord did stop just short of disaster, but not because Arthur barked.

"We stopped because we felt this breeze. We couldn't see, but it must have been a sheer 20-meter (65-foot) cliff," Lindnord says. "Arthur wasn't barking, but he was there."

The race culminated in a 14-hour kayak portion that officials wouldn't allow Arthur to take.

"They said it was too dangerous," Lindnord says. "So we left and I heard this splash, and I saw Arthur trying to swim after us. I pulled him on the kayak." The movie scene is extended for drama "but it's pretty accurate," Lindford says. "Even putting the jacket over Arthur to shield him from the rain."

Arthur joined the team in running across the finish line for 12th place.

Arthur found a new home, and medical care ... in Sweden

As shown onscreen, Lindnord decided to adopt Arthur and started jumping through the bureaucratic hurdles to bring the dog home − not to Colorado, but to Sweden − for medical treatment for long-festering wounds. "The blood work showed, just as in the movie, that Arthur would have survived for only a couple more weeks," Lindnord says.

The story of the stalwart stray went viral, covered by news outlets around the world. But it was especially big in Sweden. Similar to the media circus depicted in "Arthur the King," the dog and his human arrived in Stockholm to a throng of TV cameras and reporters worthy of a major movie star.

Does the dog die in 'Arthur the King'?

Arthur became part of Lindnord and wife Helena's family for six happy years. That's where "Arthur the King" stops its story. "He was not a dog to us, he was a family member," Lindnord says.

Sadly, in November 2020, right around the time filmmakers approached Lindnord about turning Arthur's story into a movie, the real beloved pooch fell ill. A malignant tumor was found on Arthur's spine.

"It all went very fast," says Lindnord, who announced Arthur's death on social media that December. "One day, we lay on the floor of the veterinarian's office together, and he gave me one last kiss and died."

"Arthur the King" is a tribute to the dog he loved.

"It's a love letter to Arthur. And not just to Arthur. There are a lot of Arthurs out there. It will open up people's minds. That stray or adoptable dog they see might be the best friend they don't know. So give them a chance."