One day American Denton Van Zan (MATTHEW McCONAUGHEY), chopper pilot Alex Jensen (IZABELLA SCORUPCO) and Van Zan's small army arrive at Quinn's compound looking for supplies and claiming to have killed dragons.

Quinn is suspicious of such claims, but when the Americans not only fend off an attack but also kill a hostile dragon, they begin to believe them and take some stock in their theory about how to kill the beasts. It seems that they've discovered that one male dragon is fertilizing the eggs of the many female dragons and have concluded that if they kill him, they'll wipe out the species. Armed with such knowledge and the belief that the creatures can't see that well at dusk, Van Zan and others then head off toward London in hopes of accomplishing their goal.

That said, you'd need an enormous can of Raid to deal with the pests in "Reign of Fire," the latest "us versus them" monster action thriller. That's because the beasties really are beasts. In fact, they're fire-breathing, insurance nightmare-based dragons straight from the Middle Ages.

Yet, this popcorn flick isn't set in the past, but rather in the post-Apocalyptic future where the knights in shining armor have been replaced by gung-ho Americans and their military might (although a token horse and battle ax are still present for good measure).

As conceived by screenwriters Gregg Chabot & Kevin Peterka (making their collective debut) and Matt Greenberg ("Halloween: H20, " "The Prophecy II") and helmed by director Rob Bowman ("The X-Files, " all sorts of TV shows), the film never decides whether it should be taken seriously or as over-the-top camp. That split personality and lack of focus prevent it from being either an exciting, kill the monsters thrill ride like "Aliens," or a goofy but still entertaining and enjoyable guilty pleasure such as "Tremors."

The film's bigger problem, though, are the many pests that end up annoying and distracting the viewer. I'm not talking about insects or the dragons, but rather all of the implausibility, faults in logic, and gaping plot holes that are so big you could, well, fly a large dragon through them.

Granted, a film about a post-Apocalyptic world decimated and ruled by dragons isn't meant to be viewed realistically or in a serious fashion. Nevertheless, and despite the need for suspension of disbelief, such fantasy films must still abide by the rules of their particular universe in order to work and be accepted by the viewer. Unfortunately, the filmmakers here have opted to ignore that cinematic tenet with subsequently disappointing results.

Beyond the questions regarding where the survivors get their fuel to operate their vehicles, tanks and helicopters, or how the electricity is generated in the remote castle, there's the overall logic - or lack thereof - regarding the dragons and the humans' interpretation of how to deal with them.

In most such man vs. beast films, the latter subjects are either intelligent to some degree or simply dumb but instinctive creatures. The option here was to go the former route, but the filmmakers don't sell the concept well enough to make us believe a dragon could figure out from where a remote attack on it originated and then fly many miles to deliver some toasty retribution.

That's not as bad, however, as the plan the filmmakers give the characters to kill the beasts. You see, the survivors have somehow figured out that there's only one male dragon that goes around the world fertilizing laid eggs like a spawning trout, and they've managed to track him to London. They then figure that if they can kill him with relatively primitive weapons whereas all of the military might in the world couldn't previously do that, they'll suddenly wipe out the entire species.

Who knows how they figure that out (or other various details that come out of the blue or don't make sense) or why the female dragons wouldn't still be around for years, decades or centuries, but the characters and obviously the filmmakers don't care.

While that might sound like nitpicky criticism for a film like this, the problem is that such questions repeatedly and unnecessarily distract the viewer from the proceedings, thus effectively removing them from any particular moment and the overall film. A few changes and minor additions to the script could have easily fixed much of that.

Alas, that's not the case, and I'm not sure if they could have remedied the extremely over-the-top performance by Matthew McConaughey ("Frailty," "The Wedding Planner"). Playing the gung-ho, bald and tattooed American savior, the actor alternates so much between being the standard Schwarzenegger-like, tough guy type hero and the overwrought ham that one isn't sure how to take and/or view his character. Some will enjoy it, while others will probably quickly tire of the histrionics.

Christian Bale ("Captain Corelli's Mandolin," "American Psycho") is far more subdued playing the standard, take no risk leader, and the two characters obviously clash. Yet, the conflict and subsequent fireworks between the two aren't as spectacular as they could and should have been and certainly aren't particularly novel.

Izabella Scorupco ("Vertical Limit," "Goldeneye") appears as the only major female character but isn't given enough to do (think of the likes of Carrie Anne Moss in "The Matrix" as a similar supporting character comparison), which also holds true for the likes of Gerard Butler ("Harrison's Flowers," "Dracula 2000") and Scott James Moutter (making his feature film debut).

As far as the dragons themselves, they thankfully don't speak like Sean Connery in "Dragonheart," and the CGI effects are decent but not breathtaking. They certainly don't capture the immediacy and danger found in the "Jurassic Park" films. The post-Apocalyptic production design is decent, but nothing we haven't seen before in countless other similar films such as "Escape From New York," "The Postman" or the "Mad Max" pictures.

While Bowman manages to get in a few good laughs - including a "Star Wars" skit for the young characters who don't know what movies are - his action scenes - while competent - aren't as effectively or efficiently staged and executed as one would like to see for a film like this.

Despite the conventional military spin on the old kill the dragon story (which "Aliens" previously did so much better, albeit with aliens rather than fire-breathing lizards), the film never really succeeds or goes far enough in being either a taut action thriller or purposefully over the top camp. Coupled with all of those pesky plot problems and the result is just a mediocre "us vs. them" escapist diversion. More hot air than actual flame, "Reign of Fire" rates as just a 4 out of 10.