As August wanes, Yale students find themselves confronted with the death of summer, while moviegoers find themselves faced with the demise of the stupid-but-fun summer blockbuster. “The Brothers Grimm” might not be the most thoughtless film of the season, but considering the caliber of its director — Terry Gilliam, who contributed to Monty Python and made “Brazil” and “12 Monkeys” — it’s hard not to be left wanting more.

“Grimm” begins in late eighteenth-century Germany, set in what would prove to be one of the movie’s many dingy gray houses. Jake Grimm (the younger of the two tale-spinning brothers, played competently by Heath Ledger) informs his mother, older brother, and ill sister that he has, rather fittingly, traded their cow for magic beans. Sadly, this version of the fairy tale is devoid of both giant beanstalk and happy endings; in the very next scene, we find the brothers 20 years later in French-occupied Germany, sisterless and sporadically mentioning “magic beans” as though it were an elephant in their dingy gray room.

The brothers are professional magic fighters, armed with the savvy of power brokers. They happily scam gullible townsfolk, making money by claiming to eradicate witches and trolls and the like. They stage the slaying of a witch (a fake witch, of course) with the help of two accomplices, but the real credit goes to spectacular CGI effects.

Unfortunately their life of tomfoolery and polka with the town sweethearts can’t last forever, and the two are hauled in by the Napoleonic government. Under threat of execution, Jake and his older brother Will (the mildly unscrupulous Matt Damon) are offered back their freedom if they can help the loathed French government find out who or what is causing mayhem in the town of Marbaden.

To Gilliam’s credit, Marbaden and many of the movie’s settings do justice to the dark imagination of “Grimm’s Fairy Tales.” In the film’s tortured town, 11 young girls have mysteriously gone missing. Even scarier, the townspeople resemble a cross between the creepy yokels of “Deliverance” and the horrifying apple-toting old women of Disney movies.

So, of course, there is a creepy forest on the edge of town. There the Grimms encounter particularly startling anomalies: their guide is a beautiful orphaned woman, she does not immediately succumb to Damon’s charms, and, worst of all, there is a legitimate supernatural menace.

The plot is littered with fractured fairy tale bits — from a weirdly sinister gingerbread man to a queen with a predictable but nevertheless surprisingly intense obsession with a mirror. Will is initially skeptical, attributing the bizarre occurrences to ropes and pulleys (or the much maligned French occupation.) But Jake shows a mostly innocent faith in the presence of magic, and it is perhaps enough to convince the audience as well.

It is hard to find fault in a movie so seemingly honest and light on gimmicks. But, after a two-hour time investment — one of which is spent in developing fairly stock characters (think normalized versions of Steinbeck’s George and Lennie) — the film never pays off with genuine emotion, let alone adventure. Why the bodily function jokes? And why overuse make-up and costume to downplay the beloved good looks of two proven leading men? Even the superficiality of romance could have been the spark to redeem an otherwise sparkless film.

The film features more gore and gloom than necessary for a film whose audience will be at least in part composed of young children. (After all, the crushing of a kitten in a torture device is a bit gratuitous.) To be fair, the original Grimm storylines had their own fair share of darkness, but it was usually balanced by glittery morals.

Yet the major challenge of artfully retaining the atmosphere of “Grimm’s Fairy Tales” is handled admirably. Gilliam manages to update and adapt very old stories for modern audiences — which is much more than you could say of recent fare like “Alexander” or “King Arthur.”

The film’s mix of historical fiction and fantasy can seem disappointingly aimless. At the very least, “The Brothers Grimm” is a visually appealing work driven by creative ideas, but it gets tragically lost somewhere between “Pirates of the Caribbean” and “Monty Python and the Holy Grail.”