For centuries, northern Spain's Camino de Santiago has drawn pilgrims and tourists from worlds away to walk its venerable path, 500 miles that culminate at the towering Santiago de Compostela Cathedral.
From a small town along that path, a little brown-and-white dog must have seen many of those boots walking his way ... and passing him by.
It seemed like the dog, malnourished and homeless, would need a miracle if he was ever going to get back on his feet again.
Earlier this month, he had been fished out of a pool, sick and hungry, but instead of helping, kids encircled the dog and proceeded to kick a soccer ball at him.
That's when Mark O'Guinn and Jennifer Vandersmissen, a couple of Camino pilgrims from the San Francisco, California, came across the dog.
"We came out of a pilgrim's dinner and had some beers and were feeling pretty good," Vandersmissen tells MNN. "All of a sudden, all of the pilgrims walked into the courtyard and were staring at this dog.
"He was very malnourished. He was dehydrated."
But, unlike many of the people who came before them, this couple didn't keep walking. Instead, O'Guinn heaved the little hobo up on his shoulders. And from that broad vantage point, the dog they called Rio would see more of the world than he had ever known.
But first, Vandersmissen and O'Guinn took Rio to a kind-hearted veterinarian, Dr. Alejandro Valls, who examined and treated the dog.
Vandersmissen also coordinated with Beverley Farmer of Podenco Friends, a Spain-based rescue that finds homes for podencos like Rio. She explained that at the end of their pilgrimage, they would like to bring Rio home with them.
"Even communicating via messenger, her enthusiasm is infectious and is very keen to help the podencos when she returns back to the U.S.," she tells MNN. "Rescue comes in many different formats and although I didn't directly rescue Rio, I can certainly help so he finds his forever sofa in the USA."
The couple would have to extend their stay to accommodate the mandatory 30 days Rio needed after his rabies vaccinations before he could enter the U.S.
The couple didn't think twice about it, changing their itinerary and renting an apartment in Spain.
But they also felt that Rio was an important part of their pilgrimage.
"We feel it's Rio's destiny to finish, as is ours," Vandersmissen says.
So for days, the little dog alternated between the arms of O'Guinn and Vandersmissen , while they continued on a journey that typically takes between 35 and 60 days.
When their arms failed, the couple would tuck Rio into a backpack "like a folding chair."
And, because the road was long and hard on dog paws — and because there was nary a hostel that accepted dogs — the couple rented bicycles to hasten their journey.
Throughout it all, Rio has been a model travel companion. (MNN caught up with the family on the ninth day of their journey together.)
"He's been really terrific," says O'Guinn, who is a dog trainer in California. "He's very well-mannered. He's friendly with most animals. He's really incredibly adaptable. And most importantly, he's been incredibly patient."
"The only real problem we have is potty training," Vandersmissen adds with a laugh. "He doesn't squat. He just starts peeing while he's walking."
Fortunately, Rio doesn't have to do much walking at all. For a dog who spent so much of his life peering up at passersby from the ground, it must seem like he was being borne into the air by angels.
But soon, Rio will fly even higher and farther. Once they reach the end of their pilgrimage at Santiago de Compostela Cathedral, the new family will take a detour to Beverley Farmer's podenco sanctuary some 400 miles away.
And then this little podenco will take to the air again, where his own personal pilgrimage will finally end, at the holiest shrine of all: a real home in San Francisco.
"One moment he was a lost and frightened dog," Farmer writes in a Facebook post. "Now, he has people who love him and a forever home."
Want to follow Rio's journey? Check out the Facebook page for Podenco Friends.