As anyone familiar with the novel The Road already sees coming, the film adaptation of Cormac McCarthy's Pulitzer winner can be a difficult thing to behold.

As anyone familiar with the novel The Road already sees coming, the film adaptation of Cormac McCarthy's Pulitzer winner can be a difficult thing to behold.

The tale of a father (Viggo Mortensen) and young son (Kodi Smit-McPhee) traveling south after an unexplained apocalypse toward the hope of warmth and sunshine, it takes place in a vast, dead environment nearly bereft of all colors but brown and gray, hauntingly photographed by Javier Aguirresarobe.

The quest to survive has stripped the humanity from most of the humans still remaining in the landscape. This dark matter could have something to do with the film being released a year after its original opening date in fall 2008.

But as director John Hillcoat (The Proposition) explained to reporters during a press conference with his cast at the Toronto International Film Festival in September, a source of warmth exists at the center of both book and film: a deep, loving bond between a father and son facing extreme circumstances.

"As Cormac said, [it's] about human goodness," he said. "It's really about how valuable life is, and what's special about it. I have an eight-year-old boy, and it's made me think a hell of a lot about where we're going, to cherish what we take for granted, basically.

"When I was referencing other films, I was looking at father-and-son relationships," Hillcoat recalled. "I was actually quite surprised when I discovered that the vast majority of movies out there, in terms of fathers and sons, tend to be tyrannical fathers or absent fathers. To see such a moving love story, I think, made this material extra special.

"The apocalypse was just the background," he continued. "The question is asked, 'What happened?' That's irrelevant because actually it's about this journey. If, God forbid, anything happened to such a degree, there wouldn't be the analysis, you know? Anyone that survives would try and keep surviving."

Elaborating on Hillcoat's thoughts, Mortensen said, "That's a device in this story to exaggerate what anybody could understand: What's going to happen to my kid if I'm not around for a few hours? What's going to happen if I'm not around forever? I think The Road has had more universal appeal than any other McCarthy book, including No Country for Old Men, because anybody, any culture can understand that fear."

In the course of filming, a genuine bond also formed off-screen between Mortensen and his now 13-year-old costar. Well known for immersive preparation for his roles - for example, some time with the Russian mafia for Eastern Promises - Mortensen led McPhee on a slightly different path for this film, with its corpse-strewn settings and meals of raw insects.

"One of the things we did before the film started, we went to the Bodies exhibit," McPhee explained. "That kind of helped with the movie. We went to some Mexican places in Pittsburgh (one of several shooting locations) and ate some cockroaches and stuff, crickets. I don't know if you want to know the rest."

"We're not at liberty to discuss," his costar joked.

For Mortensen, the ultimate success of the film is all about McPhee, the character he plays and the connection they share.

"The boy keeps [my character] alive, keeps him in the present as much as the dire circumstances do," he explained. "Otherwise, the guy I play probably wouldn't have lasted, he would be just consumed with sadness and regret and missing the world that was.

"This movie wouldn't work if Kodi wasn't in it, really," Mortensen added. "That relationship hinges on a boy giving an amazing performance, which he did. I am always going to be grateful that John found Kodi and chose him to play the boy in this movie, because that's what really makes it work. I didn't think of him as a kid actor. I just thought of him as a really good actor."