The frustrating thing about “Art School Confidential” is that it is so sensational for about 45 minutes. For one half, director Terry Zwigoff and writer Daniel Clowes (reuniting for the first time since “Ghost World”) craft a black comedic satire so funny, so outrageous, so stinging in both humor and observation, it borders on becoming an instant classic.

Normally this would be a cause for celebration. Here it becomes a cause of great despair. Why? “Art School Confidential” collapses, almost suddenly, and when it falls it hits the ground in so many tiny little pieces it becomes nearly impossible to imagine how they could be assembled into something worthwhile ever again.

An adaptation of Clowes’ graphic novel, this is the story of a nebbish young man named Jerome (Max Minghella) who aspires to be a great artist. He enrolls in the semi-rundown Strathmore Academy to make his dreams a reality, undeterred even when one of his professors (a thoroughly smarmy and delectable John Malkovich) ominously proclaims, “Only one out of one hundred of you will ever make a living as an artist.”

Jerome’s enthusiasm ebbs when All-American boy Jonah (Matt Keeslar) starts winning all the kudos from his classmates and professors for his rudimentary paintings of everyday objects. It gets worse when he starts romancing the object of Jerome's affections Audrey (Sophia Myles), a beautiful artist’s model who is also the daughter of a famous Strathmore graduate. Soon, the budding artist’s bubbly personality is replaced by depression and anger, Jerome starting to emulate the musings of another graduate, the angrily drunken failed artist Jimmy (a simply wondrous Jim Broadbent).

The first half of this comedy is absolute perfection. The people Jerome meets at Strathmore and the interactions he has with them are priceless. From his ultra-different roommates, budding filmmaker Vance (Ethan Suplee) and wannabe fashion designer Matthew (Nick Swardson), to a straight talking professor (a wasted Anjelica Huston) who lectures on the timeless nature of art, the uniqueness of these individuals are one of a kind. Best of the bunch is worldly student Bardo (Joel David Moore) starting another (one of numerous) freshman year at the school and intent on making sure Jerome understands exactly what he’s gotten himself into.

During these introductory bits is where “Art School Confidential” soars. Clowes’ and Zwigoff’s acerbic tastes are well suited to this satire of artists, art school and the high-strung hoi polloi who think they know better than anyone else what art is and who is worthy of viewing it. Everything here clicks, the filmmakers running and gunning like true satiric professionals. For a while it looks like this duo is going to reach the same level of brilliance they attained their last time out, images of this and “Ghost World” playing together during a late night doubleheader impossible to ignore.

Well, while that twin bill will still more than likely occur in it isn’t happening because “Art School Confidential” is any good. When this film falters and falls it does so with a crashing thud heard halfway down the block. With an inert suddenness the picture looses both its charm and its nerve, descending into a subplot about a serial killer that stalls everything out completely. Jerome becomes a bore, Bardo disappears and the ultimate identity of the killer is such a forgone conclusion a savvy audience probably figured the twist out back in the first act.

But it is the climax where the filmmakers completely unravel. Where Zwigoff had the guts to go for the jugular in “Bad Santa,” here this crackerjack team of cinematic craftsman decide on a twist almost insulting for its obviousness. It is the easy resolution, a copout so beneath both writer and director I’m almost ashamed for the both of them that they decided to go with it. Goodwill is drained away to its nether point, the magnificence of the first half gone in a flurry of poorly thought out misdirection and idiotic moralizations so sophomoric they belong someplace else.

Pity, because for a while there I had hopes this was going to be a winner. For a while it’s fresh, funny and bitingly brutal. But like an essay with a good thesis statement and a banal conclusion the movie fails to live up to this early potential, and in the same vein as a bright freshman crumbling under collegiate pressure “Art School Confidential” washes out with all the fanfare of a whisper.