Two dark figures, tattered and beaten, crawl across the screen. Fighting the unforgiving desert sun, they fortuitously stumble upon a decades-old downed plane. Cut to the next scene: we find the heroes of Sahara windsurfing amidst the desolate landscape using the plane’s right wing as a makeshift sail, as good ole American rock blares in the background. And that’s when it hits you: you have no idea what’s going on, or even what movie you’re watching anymore.

Swerving madly from manic action sequences to bizarre pontification about ecological responsibility, Sahara’s screenplay seems to suffer from some deep schizophrenic identity disturbance. Logical continuity of genre proves to be nothing more than a temporary desert mirage in this convoluted, somewhat disappointing action movie. But that doesn’t mean that seeing stuff explode can’t be fun.

Sahara, directed by Breck Eisner and starring Matthew McConaughey, Steve Zahn, and Penélope Cruz, is based on one of a series of adventure novels written by Clive Cussler. The movie, like the books, follows the daring escapades of intrepid explorer Dirk Pitt (McConaughey), hunky marine adventurer.

Danger and intrigue have brought Dirk and best pal Al Giordino (Zahn) to Africa: Pitt believes that he has finally found an iron-side battle ship which disappeared after the American Civil War (yeah, I know, in Africa—I’m still trying to figure that one out). Here’s the kicker: the legendary ship is rumored to be carrying a cargo of lost gold.

Meanwhile, Dr. Eva Rojas (Cruz) of the World Health Organization, the latest in a proud line of pouty academic vixens, discovers a horrible, mysterious plague that seems to be originating from Mali, a republic currently locked in bloody internal turmoil.

She teams up with Dirk and Al (as dictated by the mysterious laws of action-movie cliché) and soon they’re facing a high-level conspiracy, a ruthless military dictator, and the threat of unimaginable ecological disaster. As our fearless crusaders scramble to save the world from certain apocalypse, high-paced action sequences ensue. So shotty plot work aside, how does Sahara manage to undershoot even mediocre?

Mostly, Sahara fails because it just can’t decide what movie it wants to be. Part historical adventure, part sand-swept romance, when the film’s not playing like Outbreak déjà vu, it expends way too much energy channeling eco-apocalypse thrills à la The Day After Tomorrow.

Somewhere in there, too, is a substantial amount of socio-political subtext, but it’s dropped in such a half-hearted, haphazard manner that any commentary ultimately gets lost among all the flashy explosions. Sure, such lines as “No one pays attention to Africa” pop up now and then, but they appear jarring amidst gunfire battles and elaborate speed-boat chases.

The central characters are even less developed than the plot, leaving the actors no choice but to rely on gimmicky overexaggeration. Throughout the film, Cruz doesn’t have much else to do than run, scream, wait around to be rescued, and occasionally flip her textured tresses.

McConaughey, doing his best McGuyver-meets-Indiana Jones (minus the ’80s pseudo-mullet, and the cool hat, respectively) grins and punches his way through the movie, relishing his role but not really saying a whole lot. For an alleged real-life Hollywood couple, McConaughey and Cruz have an astounding lack of on-screen chemistry.

Looming maliciously as the film’s well-groomed villain, Lambert Wilson delivers each line with silky-smooth narcissism, securing his position as the coolest, suavest French badass in Hollywood cinema.

But it’s Zahn who runs away with the film. He plays his cookie-cutter, funny-but-loyal sidekick bit with great zeal and goofy charisma. Amazingly, he even manages to project a degree of endearing, befuddled sincerity into his underwritten role.

Ultimately, the film breaks down as all plot lines are hastily condensed to expedite narrative resolution in the last few, pyrotechnics powered sequences. Granted, most of the fights and explosions are impressively well-shot and sufficiently adrenaline-rush inducing. But in the end, there’s just one too many narrow escapes, fortuitous coincidences, and astounding leaps of logical assumption.

Case in point: halfway through the film, Dirk utters something like “Obviously the contaminants are coming from the source of the underground river.” Yes, obviously. Or my favorite: “Those barrels of toxic waste over there are being taken away to be evaporated by super-conductive solar power.” Clearly.

In the end, Sahara is still an exotic, loud, and moderately entertaining flick full of flashy fight sequences and daring escapes from near-certain death. Plus lots of cool stuff blows up. Often. And to its credit, Sahara does rock out to a pumping, down-home American soundtrack.

If you’re in need of some mindless action-adventure fun, Sahara will do. So relax—buy yourself a big bucket of popcorn, sit back in your mohair-covered theater seat, marvel at all the shiny, expensive speedboats blowing up, and forget all about that six page response paper due Monday.