Warner Bros. Pictures

Christian Bale stars as John Connor in "Terminator Salvation."

If you were a young movie fan in 1963, the coolest thing you saw on screen was the band of fighting skeletons in "Jason and the Argonauts." They came courtesy of the great stop-motion animator Ray Harryhausen.

Forty-six years later, fighting skeletons are still pretty cool and Harryhausen's spirit hovers over "Terminator Salvation." Of course, special effects have taken a quantum leap since Harryhausen's days and they're the main stars in this, the fourth installment in "The Terminator" saga.

In James Cameron's original science-fiction thriller titled "The Terminator," California's governator played a cyborg from the future sent into the past to alter the course of history. Arnold Schwarzenegger was the relentless machine out to destroy mankind's hope for survival against a world dominated by machines. Call it typecasting but Arnold did a pretty good job of playing a muscular machine. He's not physically present here but his CGI reproduction is.

This episode begins with an inmate on death row who donates his body to a persuasive doctor (Helena Bonham Carter) who wants it for medical experimentation. Jump to the post-apocalyptic world of 2018, when mankind is in a brutal war with machines that have developed the ability to think and reproduce themselves in a variety of deadly forms, including malevolent metal skeletons.

John Connor (note the initials) is still the Messiah figure ordained to save mankind from the machines. His duties are twofold: one is to lead the resistance against the machines; the other is to save the teenage version of his father so the prophecy can be fulfilled. This brings up the conundrums of time travel so don't ask. Just buckle your seat belt and hang on.

Christian Bale is on hand as Connor and he plays him with an urgency that suits all the screeching destruction in the movie. Sam Worthington plays the condemned inmate from the past who pops up again and may or may not be what he seems. Moon Bloodgood plays the fighter pilot who gives him the benefit of the doubt. And Anton Yelchin plays John's time-traveler pop.

The movie creates a compelling post-apocalyptic landscape of dust and winter sun littered with the residue of human consumerism. It also achieves a convincing, techno-grunge conflict between malicious machinery and human resourcefulness.

Mankind had become addicted to increasingly sophisticated gadgetry and now the gadgetry wants payback. It's not nice to fool mother iPod.

Director McG cut his filmmaking teeth on the "Charlie's Angels" movies and the very human and inspirational "We are Marshall." None of these represents the kind of action boot camp that would prep him for a heavy-metal throw-down like this. He's apparently a quick study because he has the action chops of a veteran. He respectfully pays tribute to George Miller's "The Road Warrior": a feisty, feral kid fighter; rip-roaring motorcycle pursuits; and a commitment to making a movie that incinerates the tachometer.

The acting is uniformly decent and adequately serves the action. There's not a lot of depth to the characters though Worthington gives the human element some inner conflict and tough-guy anguish.

This, after all, is an action movie with a big and bold capital A. As such, it's a headlong entertainment machine that races across the screen without any pretensions otherwise.