Mal Reynolds (Nathan Fillion), the hard-bitten captain of the spaceship Serenity, isn't given to despair, but there's a point in Joss Whedon's intergalactic odyssey when even he starts to give up hope. He and his ragtag crew are on the run from the omnipotent Alliance, not to mention the ruthless, cold-blooded contract killer (Chewitel Ejiofor) they've hired for the job, and it turns out the human cargo Mal's been hauling, the traumatized psychic River (Summer Glau), may be as dangerous as she is desirable. What's a salty space pirate to do? Have faith, proclaims Ron Glass' itinerant preacher. "Only one thing's gonna walk you through this," he tells Mal. "Belief."

If that sounds a bit weighty for a star-spanning adventure, there's more emotional freight on the way. But if anyone's entitled to proclaim the virtues of believing in the impossible, it's Joss Whedon. Three years ago, the Buffy creator was the heartbroken author of the TV series Firefly, which Fox strangled in its crib after airing only 11 of 14 completed episodes. But after a vigorous campaign by bereft fans and brisk sales of the Firefly DVD, Whedon found himself behind the wheel of its unprecedented big-screen sequel, Serenity, which wraps up many of the series' lingering questions while leaving the door open for newbies (not to mention potential sequels). Attempting to capitalize on the series' dedicated base, Fox began screening the movie to fans several months in advance, more than 70 times in all. Each screening was prefaced by a taped thank-you from Whedon, which read in part, "Failed TV shows don't get made into movies unless the cast, the creator and the fans believe beyond reason."

The similarities between the impossible tasks faced by Serenity's crew and its creator are coincidental, Whedon says, but he acknowledges the role blind faith plays in both their successes. "The faithfulness of the fans was one of two essential factors," he says, "the other being absolutely staggering luck."

Serenity focuses on the conflict between Mal, a disillusioned "independent" who was part of a quashed revolt against the Alliance, and Ejiofor's coldly fanatical foot soldier, called "The Operative" in the credits but pointedly unnamed in the film itself. The Operative is a pragmatic zealot who believes in the Alliance's promise of "a better world" while accepting that his actions will leave no place for him in the utopia he wants to create. Mal, by contrast, stands for something in spite of himself; despite his devil-may-care facade — when he's told a proposed action is "not your way," he quips, "I have a way?" — he's an idealist through and through.

"All cynics are frustrated idealists," Whedon observes. "Other people are OK with the way things are. [Mal's fellow veteran] Zoë is a soldier, so she can handle the fact that they lost. She can get married; she can have a real life. But Mal's that classic character who's lost so much he doesn't want to lose again." Although Mal most resembles Casbalanca's Bogart, Whedon traces his lineage from The Searchers' Ethan Edwards through Han Solo — which might explain why Serenity is truer to the spirit of the original Star Wars than anything since The Empire Strikes Back.

Although few reviewers noted it, Serenity's battle between unprincipled zealots and disillusioned rebels has obvious resonances with the current political landscape: The Operative might be any number of Bush appointees, spouting high-minded rhetoric but acting utterly without principle, while the Serenity's crew makes an apt stand-in for the dispirited left, scraping out an existence on the fringes while they regain their strength of will. The resemblance, Whedon says, is entirely intentional, though he worked to keep the allegory open-ended. "It's no secret that my politics are liberal," he says, "but I wanted the movie to be political without being partisan. To some people it could be the individualists versus big government, or people can say the Alliance is America in Iraq. You can read different things into it." (For the latter interpretation, check this quote from the London Telegraph: "[The Alliance] is the most enlightened society in the galaxy, but they're making the mistake any big power makes, which is to assume that their version of enlightenment should be spread everywhere.")

Mal, Whedon says, "is a much more reactionary character than I am. I don't think we'd get along." But he clearly admires his creation's tenacity. What makes Mal stronger than his nemesis, Whedon says, is that "The Operative lacks context. Context sort of took Mal out of the game for a while. But The Operative believes in a system that he does not embody, whereas Mal is exactly what he believes."

That inescapable self-definition is ultimately what saves Mal from Serenity's greatest villain, which is not The Operative or even the Alliance, but apathy. It's apathy that keeps Mal "out of the game" and keeps the Alliance's citizens blind to their government's actions, and it's apathy that, when the Serenity's crew finally penetrates the mystery The Operative is sworn to protect, turns out to have been refined to a lethal force. Again, the parallel is deliberate. "There's no question that apathy, and just letting things happen, has really hurt this country," Whedon says. "There was a time when people looked at government and the Constitution as this extraordinary living thing, and the country itself depended on the difference between good and evil." That feeling explains all by itself why Serenity and Firefly reference both classic Westerns and science fiction, looking to the past as well as the future.

As for the future, well, Serenity's ending is only guardedly optimistic; the Alliance's corruption is exposed, but there's no hint as to whether its citizens will pay heed. And the series' future is similarly dim, since Serenity opened in a respectable but unspectacular second place at the box office last weekend. But stranger things have happened. You just gotta believe.