How far would you go to help a sick child?

That question stays with you throughout "The Horse Boy," Michel Orion Scott's moving documentary about one Texas couple's journey to Mongolia to heal their autistic son.

When Rowan Isaacson was diagnosed with autism at age three, it seemed to his parents "like God had kicked us in the face."

"We had so many conflicted feelings," says Rupert Isaacson, Rowan's father, the film's producer and author of the book "The Horse Boy."

"When your child has a condition that medicine understands, at least you can say this is the treatment and here's what we're going to do. There is no such thing with autism."

Thanks to a neighbour's horse named Betsy, however, the distant, tantrum-prone youngster made a surprising connection that altered his life forever.

At the age of four, Rowan ran into the corral where the old mare was kept.

"By normal standards he should have been trampled." says Isaacson, a former horse trainer and humanitarian activist.

Instead, Betsy dipped her head and chewed her mouth in submission.

"I had never seen a thing like this happen so spontaneously," says Isaacson. "Betsy completely modified her behaviour around Rowan. I've since discovered that many horses will do this around special needs children. They respond instinctively to children that need protection."

Remarkably, Rowan's language skills began to improve after rides on Betsy with his father.

The sight stunned Isaacson and his wife, psychology professor Kristin Neff.

Equine therapy and shamans not for everyone

Traditional medical treatments had generated little improvement in their son. But the boy seemed engaged with the world when riding and petting Betsy.

"Equine therapy doesn't work for 100 per cent of kids. It gets good results in 55 to 80 per cent of children. Rowan was one of the lucky ones," says Isaacson.

Stirred by that tiny glimmer of hope, Isaacson hit on the daring idea of travelling to the nomadic camps of Mongolia, where horse culture and shamanistic healing are still prevalent.

It was a huge leap of faith, but one the couple were willing to make.

"It took two-and-a-half years to put the trip together, even with my contacts. You can't just email a shaman or call them up," says Isaacson, who first gained international recognition for his writings about the plight of the Kalahari bushmen of Botswana.

"I'm not saying that this decision would have been right for every parent," Isaacson told CTV.ca. "I simply thought if we went there, rode across the steppe and visited these healers, what might happen for Rowan? Might there be some positive outcomes?"

Even as they travel to Mongolia, drive for hours into the steppes and journey to a sacred mountain by horseback, Isaacson and his wife still have their doubts.

That skepticism, anxiety and faith-filled bravery makes Scott's documentary feel very real and compelling.

The film's sweeping vistas and lulling sense of quiet also compliment Rowan's remarkable breakthrough moments, particularly after one elaborate ritual led by a healer.

The shaman announces that Rowan will stop soiling his pants and screaming violently the very next day.

His prophetic words prove to be true.

"When I saw Rowan walk by the river and clean himself it was like a get out of jail card. I knew in that instant his life had changed for the better," says Isaacson.

Rowan's mysterious turnaround, like his autism itself, is hard to comprehend. But, Scott puts it into context in this upbeat, engaging ride via interviews with autism experts. They include Dr. Simon Baron-Cohen (the cousin of "Borat" star Sacha Baron Cohen) and Dr. Temple Grandin, a professor of animal behavior at Colorado State University who has autism.

"Rowan isn't healed (but) he is functional now. He tells stories and talks. He even wants to make movies," says Isaacson.

"I'm not telling every family to get on a plane and do what we did. Let the child lead you to what engages them. Get them into nature. The quiet calms them and lets their intellect emerge. There is intellect there," says Isaacson.

"You just have to find the way to it."