First-time feature director Joss Whedon managed a minor miracle when he rescued his inspired idea about a vampire-fighting Valley Girl from the wreckage of the 1992 comedy-horror film BUFFY THE VAMPIRE SLAYER and reconfigured it into a consistently witty TV series in which the clichés of high-school angst were played out as an apocalyptic battle for the soul of the world. He pulled off another by reviving the 2002 sci-fi series Firefly from its manhandling by Fox television — episodes were aired out of order when they weren't preempted, and it was ignominiously canceled with several segments unaired. A smart, engrossing Western in sci-fi drag, the film opens with a tightly wound spiral of false realities. First, a sugar-coated classroom lecture lays out the history of an oppressive interplanetary Alliance that, 500 years in the future, rules a cluster of developed planets colonized by refugees from overcrowded Earth, while leaving the less desirable outerworld colonies to their own rough-and-tumble devices. The lecture segues into a disorienting dream sequence that in turn dissolves into a surveillance recording showing how Dr. Simon Tam (Sean Maher) rescued his sister, River (Summer Glau), from a supposedly secure Alliance research facility. The viewer is a nameless Alliance assassin (Chiwetel Ejiofor) charged with getting River back who doesn't yet know the siblings are traveling with Captain Malcolm Reynolds (Nathan Fillion) and his motley crew of space brigands. There is, of course, more to River, a delicate-looking 17-year-old, than meets the eye; not only is she a powerful psychic, but she's been trained and artificially modified into a superwarrior. Her training, unfortunately, has left her frighteningly unstable, prone to hallucinations, enslaved to subliminal prompts and tormented by someone else's memories, memories that involve someone or something called "Miranda." Like TV's Buffy, the movie is driven by slyly clever dialogue loaded with sneaky character insights. Muscle-bound mercenary Jayne (Adam Baldwin), glamazon Zoe (Gina Torres, of TV's Cleopatra 2525) and smart-mouthed pilot Wash (Alec Tudyk) are broadly but sharply drawn; by the time bad things start happening to them, it counts. And it features truly monstrous bogeymen in the Reavers, cannibalistic renegades who, legend has it, went to the edge of the universe and were driven mad by the abyss. The truth is more awful and precisely wrapped into one of the story's many sharp but perfectly logical twists. Fans of the short-lived TV series are this film's built-in audience, but you don't have to have seen a single episode to enjoy it immensely.