Wahlberg plays an adventure racer who forms a powerful bond with a stray dog in Simon Cellan Jones’ film based on a true story.

Don’t be fooled into thinking that the new film starring Mark Wahlberg is an adventure movie. Sure, it depicts athletes participating in the Adventure Racing World Championship, an annual competition in which teams of four must traverse 435 miles through rugged terrain. It involves running, trekking, climbing, kayaking and mountain biking, and seems truly bonkers. But just as your eyes begin to glaze over watching Wahlberg and his co-stars sweating and grunting their way across the jungle, someone comes along to save the movie. He’s the title character, a scruffy dog who will steal your heart and transforms Arthur the King from a run-of-the-mill sports drama into a love story.

He is, perfect, however, for playing the sort of obsessed, win-at-all-costs character who clearly spends much more time at the gym than your typical husband and father. His Americanized character, Michael, is shown in the opening scenes of the movie competing in a previous competition in which he nearly kills his four teammates with his reckless decisions, and still winds up losing the race.

Interspersed with the scenes detailing Michael’s preparations are ones introducing us to Arthur, an injured, scruffy street dog who’s clearly seen hard times but is resourceful enough to hitch a ride on a passing truck when being chased by two larger canines.

Michael makes Arthur’s acquaintance during the team’s first rest stop after their jungle trek, when he’s impressed by the dog’s unwillingness to beg despite being obviously hungry. Michael gives him a meatball anyway, not realizing that he’s sealing an irreparable bond between them.

Some 200 miles later, after his team nearly runs into catastrophe while making a shortcut that involves mountain climbing and ziplining with their bicycles attached (it’s a truly harrowing sequence), Michael is astonished to encounter the dog again, having no idea how he managed to follow them through the rough terrain. Dubbed “Arthur” because of his noble demeanor, the dog soon becomes an invaluable member of the team, keeping up with them every step of the way and even saving Leo’s life by preventing him from unwittingly walking off a steep cliff in the dark.

Obviously, being a dog lover goes a long way toward one’s enjoyment of Arthur the King. But even if you’re not, you won’t be able to resist this canine thespian who manages to convey a world of information merely through barks. And he doesn’t even need those. When Michael sits down to tell him that, sorry, he won’t be able to kayak with them, Arthur looks at him with the most doleful, poignantly sad eyes since Charlie Chaplin gazed at the formerly blind girl at the end of City Lights.

Is all of this manipulative and cheesy? Yes, and yes. But it ultimately proves irresistible, and will be especially so for younger audience members. Parents should be advised that taking their children will inevitably result in pleas for a dog of their own immediately following the film.

Wahlberg infuses his performance with genuine heart, making his character’s falling in love with his new canine companion fully believable. And Juliet Rylance is fine as Michael’s supportive wife, even if she’s forced to spend most of the movie staring at a computer and saying lines like “Michael, what have you done?” and “Way to go, Michael!”