"Liberty Heights" is like the trolley lovingly restored a few years back to ride the half-mile of track at the Baltimore Streetcar Museum. It's a beautiful contrivance, but it doesn't go anywhere.

For the fourth time in his career, Barry Levinson revisits the magic city of his youth, only this time the magic eludes him. "Liberty Heights" fizzles out after a promising beginning, paying off on none of its premises, edifying no one and somehow not reaching the level of the director's first three Baltimore films.

Set over the school year of 1954-55, it basically follows as a set of youngsters--mostly a teenager and his older brother, evidently a law student--learn that . . . well, Levinson is basically unable to make clear what they learn or why we should care about it.

What's missing from "Liberty Heights" isn't a sense of place--dowdy old Baltimore has never looked so majestically leafy and golden--but a sense of character. Who are these people? What's inside them? Are they real or representative? Why are there so many of them? It's as if the writer-director has taken a motif from each of the preceding films--male bonding from "Diner," shrewd business practices from "Tin Men," a sense of irrefutable change from "Avalon"--and crushed them together without much care or coherence.

That's not to say the movie is joyless. It is, in fact, joyous in the Levinson way: sly, off-center, quietly funny, full of wisecracks from wise guys, deadpan observations from a twisted point of view, and more than a little irony. Many of the scenes play brilliantly, and that's Levinson's key talent. He's a sketch writer, not much of a storyteller.

Basically it plays three tales against each other. In one of them, Ben Kurtzman (Ben Foster), a senior at Forest Park High in the very Jewish glades of Charm City (it's one of the most Jewish cities in America), becomes transfixed with an African American girl (Rebekah Johnson) who has just transferred in, courtesy of the Supreme Court decision. At the same time, he's beginning to learn of the presence in the world of that alien force called antisemitism: A sign at a gentile swimming club that proclaims "No Jews, Coloreds or Dogs" upsets him.

Then there's his father, Nate (Joe Mantegna), a benevolent gangster who runs the numbers racket behind the front of his burlesque house. Nate runs into big trouble when a black drug dealer, Little Melvin (Orlando Jones), not only hits the number but hits it on a $50 bet, which wipes Nate out. Since Nate is more like the appliance store owners of "Avalon" than the gangsters of "Bugsy," he can't kill Little Melvin, but has to work out ways to come to terms with him. This is a miscalculation; Little Melvin won legitimately and if Nate can't pay, he's got to go bust. That's the game he chose to play. But the film expects us to empathize with Nate rather than Mel. I say: Nate, pay up or get out of town.

And finally, older brother Van (Adrien Brody) has connected, by a complicated route, with a self-destructive gentile princess named Dubbie, and is astonished, even a little intimidated, by the depth of her hungers. This is a particularly lame plot line; we don't learn a thing about Van. He's easily the dullest character in the story; he seems utterly mystified by what's happening to him, unchanged by it, in fact barely conscious. As for Dubbie (Carolyn Murphy), she's the fevered product of the imagination of someone who's seen too many Grace Kelly videos.

Levinson loves to run montages of turning points and finally the climaxes in each of these stories against each other, somewhat like the climax of "The Godfather" all those years back. But what's driving the sequences--and what drives the movie--is the rhythm in the editing, nothing in the stories themselves, which pretty much play flat.

And for a movie apparently driven (according to press interviews) by Levinson's need to confront antisemitism as he first discovered it, the movie is frighteningly full of stereotypes. The Jews are all smart businessmen or sensitive boys; the blacks are ignorant and violent (a kidnapping, played for comedy, is another dubious plot invention) but with exaggerated comic diction and fried-egg eyes, the WASPs all drunken sybarites hellbent on self-destruction while quipping dryly.

Indeed, the more interesting and complicated characters are subsidiary. Yussel (played by David Krumholtz) goes from someone utterly proud of his Jewishness (so proud he'll take a beating on its behalf) into a heritage-denier under a blond dye job; a stripper discovers that peeling out of her street clothes is more effective than peeling out of her spangled costume; a beatnik gangster tries to calculate new wrinkles to the numbers game, like a mini Aba-Daba Berman, Dutch Schultz's math genius. Levinson throws this away, as he throws away the great Bebe Neuwirth in a nothing role as Ben's mom.

The movie is somehow impolite; it presumes a welcome, rather than earning one. It asks us to be grateful that it's even there, not to love it for the work it does.

Liberty Heights (122 minutes, at area theaters) is rated R for profanity and sexual situations.

CAPTION: A few blocks short of "Heights": From left, Ben Foster, Bebe Neuwirth, Joe Mantegna and Adrien Brody in "Liberty Heights."