For centuries, the Maya ruins -- the remnants of an ancient empire -- have dared outsiders to unlock their secrets.
Two years ago, a controversial movie director decided to take that dare. The result is Mel Gibson's new film, "Apocalypto," which opens on Dec. 8.
One of the most physically harrowing shoots in Hollywood history began because Gibson decided it would be fun to make a "chase" movie.
"My first instinct," Gibson said to ABC's Diane Sawyer, "was, 'Wow. Chase movies, you know? What kind of chases? Let me see: There's car chases. There's plane, bus, boats.'"
Gibson ultimately decided nothing could match the heart-pounding terror of a man literally running for his life.
His hero in "Apocalypto" is named Jaguar Paw, after the sacred Mayan jaguar with green eyes.
The actor who brought Jaguar Paw to life is Rudy Youngblood, a 25-year-old Native American who had never been in a movie before, and whom Gibson describes as an "everyman kind of guy."
A Voyage of Personal Discovery
In the movie, Jaguar Paw is a young Maya villager fleeing from bloodthirsty tribal rulers.
The Maya of the late 1500's believed that human sacrifice was nourishment for their gods, and planned to kill Jaguar Paw.
After his escape, Jaguar Paw encounters one terrifying peril after another, enduring a kind of odyssey through all our -- and Gibson's -- most primal fears.
In total, "Apocalypto" boasts a cast of 3,000 American Indians, nonactors speaking only Spanish or the native Mayan language, Yucatec.
For eight months, they struggled together through the harsh conditions and blistering heat.
By the time the movie was over, Gibson says, the actors all became indestructible warriors.
"There was a lot at stake for these guys," he said, "but they all pulled it off. It was great."
Gibson's guide into the history of these legendary cities was Richard Hansen, a professor of anthropology at Idaho State University.
"One of the great things about 'Apocalypto,'" Hansen said, is that "it brings [the ancient world] to life here. It's an opportunity to see a city like this being brought to our conception of what it would look like originally."
'Everything Has a Beginning and an End'
Gibson explained the film's title to Sawyer:
"'Apocalypto.'… It's Greek, of course. It just means a new beginning or an unveiling -- a revelation."
When asked whether it related to the biblical revelation, Gibson said: "Everything has a beginning and an end, and all civilizations have operated like that."
Gibson says the movie has universal appeal because on a basic level, it addresses fear.
When asked whose fears we see in the film, Gibson said: "Boy, they're most people's. I think a lot of them are mine."
"People like scary stories," he said. "There's a fascination with fear themes, and we want to face those things in a weird, subconscious way."
Gibson knows all about facing fears: He made his name taking chances -- as an actor, and then as a director.
No one in Hollywood thought "Braveheart" would be an Oscar-winning commercial success, and then he spent $30 million of his own money to bring "The Passion of the Christ" to the big screen.
The film has earned almost $1 billion worldwide.
When it comes to risk, though, Gibson has made it clear that nothing in his career ever matches the terror he faces every day in his battle against alcohol and lifelong addiction.
Four months ago, after a long period of sobriety, Gibson fell back.
In July, there was the drunken anti-Semitic outburst at a police officer who was arresting him for drunken driving.
In an interview with Sawyer on "Good Morning America," he talked about those anti-Semitic slurs, and said that he hoped he could redeem that awful moment.
Today, Gibson says that he's continuing to meet privately with members of the Jewish community and that he's grateful to those who believe in second chances.
Despite his renewed commitment to sobriety, Gibson still seems drawn to controversy.
He now says that "Apocalypto's" themes of a civilization squandering precious resources, including men in war, make him think of the Bush administration and Iraq.
When asked whether the film was a warning, Gibson said: "In a sense. It's a little bit like. … Look at this civilization. They're not around anymore. What were they doing? Why?"
"There were wars," he said. "There were famines. There was destruction of the environment. There was conspicuous consumption. … No regard for human life at some points."
In the film, there are answers and hope that take the form of starting over: living with respect for Earth, peacefully and without fear.
While in the jungle filming the movie, Gibson decided it was time for him to conquer a lifelong fear of heights.
After Youngblood made several terrifying jumps off a building, the crew goaded Gibson into trying it himself.
"They're hauling you up and everybody gets smaller and smaller and smaller, and the winds starts. … It's a funny feeling dropping that height."
The one-time action star is now 50 years old, a veteran director who has made a film in Aramaic, and now one in Yucatec.
He says that next, he'll "do only in English. I think maybe something funny."
Gibson hopes to emerge from a year of crisis into a year of transformation.
"It begins again after a massive upheaval," he said, referring to the Maya Apocalypto. "But that happens even in our lives. Our lives are a microcosm of that, you know. … Wake up. Be new again. Try again. People have done it over and over again. People do it."
"Apocalypto" is a Touchstone Pictures production. Touchstone is a division of The Walt Disney Co., the parent company of ABC News.