Clint Eastwood’s Mystic River, which opened this year’s New York Film Festival on a somber but resonant note, is perhaps the finest western ever to be set in South Boston. Huddled clapboard houses substitute for the raw-plank architecture of the frontier town; an industrial bridge provides background sublimity in the absence of mountains. As always in an Eastwood western, the action takes place in an enclosed community that prefers to operate by its own rules; and as always, terrible secrets haunt the characters. Terrible wrongs are avenged and redoubled.

Of course, some viewers prefer to classify Mystic River with Eastwood’s police movies; and they’re not entirely wrong. In the role of Sean Devine, a detective with the Massachusetts state troopers, lean and clean-featured Kevin Bacon closely approximates one of Eastwood’s own tight-lipped cops, never raising his voice, continually struggling to hold himself in. But the Eastwood detective usually pursues some taunting, demonic version of himself. Devine must contend with a pair of contrasting alter egos, both of them figures from his childhood on these streets: Jimmy Markum (Sean Penn), the big man in his little neighborhood, and Dave Boyle (Tim Robbins), who shuffles meekly around the bars and back porches and sometimes thinks he’s one of the Undead.

He is, at a minimum, unfinished. That much is obvious from a square of sidewalk into which Dave and his buddies scratched their names some thirty years ago: Jimmy, Sean, Da. Now the memory of the event that interrupted Dave’s hand is literally set in concrete, right on the street: the visible sign of something lost in him, something irremediably broken in the neighborhood.

What might turn that lingering pain into a present danger? A saloon, a six-shooter, a code of manliness.

Based on a novel by Dennis Lehane, Mystic River tells about guilt and suspicion in a working-class neighborhood–about young people abused and murdered, about generation after generation raging for revenge. Clearly, this story moved Eastwood to a seriousness he hasn’t practiced since Unforgiven and A Perfect World. In the less ambitious projects that have piled up in recent years, the unfussiness that is one of his chief virtues as a director has sometimes turned into his biggest flaw; you wondered, during certain scenes of Space Cowboys or Blood Work, whether you were seeing the movie or the dailies. In Mystic River, though, Eastwood’s clarity and strength are apparent from the start, even in the casting of the briefest roles. It’s enough, in the devastating prologue, to see three boys playing hockey in the street to know which will grow up to be Sean Penn and which is doomed to become Tim Robbins. When the grown-ups take the screen, their sureness matches the director’s. The performances seem to enter their bodies straight up from the pavement.

Robbins is the one who deploys his technique most openly: pushing a Boston accent against his hard palate and up into the nose, inventing a complete body language of shrugs and hesitations. A slight studiousness hangs about the performance; and yet he’s also the actor who becomes the most daring and spontaneous. Dave is falling apart; and Robbins really lets the pieces crash. You see the effect not so much when he gets to scream–anyone can flail about–as in the quieter scenes, as when he tells his son a bedtime story that runs out of control. Dave’s words, which are disturbing in themselves, become all the spookier for Robbins’s way of listening to himself, as if he, too, were puzzled by what’s coming out. Eastwood completes the mystery for him, shooting him against a background of infinite darkness, with only the left half of his face visible in a window’s pale light.

Eastwood subjects Sean Penn to no such murk. As Jimmy, a convenience store owner with a dead daughter and a surprisingly complicated agenda, Penn has all the forcefulness that’s been drained from Dave plus a few gallons more, despite his coming before you with a furrowed brow and gray at his temples. You sense this man is too old to be acting like the neighborhood tough; but like Dave, he’s been tugged back into the past, reverting to a role he gave up years ago. Jimmy can still carry it off, but it weighs on him, as Penn shows you. He wears his muscles like a suit of armor; he rarely hauls his voice out of the lower dungeon of his throat.

Of the three leads, Bacon must remain the most controlled, not just because the character demands it but also because he’s filling in for an icon. Sean Devine is the part a younger Eastwood would have played. Bacon, of course, is not an icon–he’s famously versatile, which precludes such status–and yet he succeeds in making the role his own, despite having to deal with the distraction of a wretchedly underdeveloped subplot. In addition to its other elements, Mystic River is a story of three marriages: Jimmy’s with the equally tough Annabeth (Laura Linney), Dave’s with the equally tremulous Celeste (Marcia Gay Harden) and Sean’s with a woman who is absent for almost the whole movie. Why is she absent? What must Sean do to get her back? How does his implied failure intersect with the other characters’ problems? The answers drop into the story very late, as if by magic; while Bacon, a consummate pro, pretends that all is normal.

This is merely to say that the film suffers from the false moments–some improbable, others annunciatory–that usually come with a Brian Helgeland screenplay. I also might complain that the rhythms are sometimes choppy (there being none of the long, fluid sequences that you found even in The Bridges of Madison County) and that the music, by the composer Clint Eastwood, ought to have been cranked down a few decibels by his director.

Minor shortcomings, in the context of everything the film gets right. Mystic River may be a western at heart, but it knows its old-style city neighborhood as few other American films do. How accurate, how just, that practically the only bright color in this movie should burst out at the very end, when two shattered families pass before the cold eyes of a cop who knows everything and can do nothing. It’s autumn, and a little parade is going down the street; people are doing their best to celebrate. Soon, you can tell, the first snow will fall; at which point the wounds will be buried still deeper, under a uniform, wan, grayish blue that hides but can never numb.

Unstately, plump Jack Black violates twenty-four times a second the comic actor’s primary rule, “Don’t show that you think you’re funny.” What do rules matter to a hurricane? When Black is blowing at full force–eyes rattling, hands wriggling, voice and pelvis shooting about in parallel abandonment–he’s wild enough to turn himself into a one-man pomp-rock band, without benefit of costumes, props or musical accompaniment. He performs this trick, along with many other nifty turns, in School of Rock, a film that should be avoided by anyone who dislikes laughter, children, music and good cheer.

Black’s character in the film, a would-be guitar god named Dewey, is one of those cases of arrested development so common in the beer-soaked caverns of rock. Although he’s already well into his 30s, Dewey has no adult sexual relationships, financial resources or domestic space. Then comes a stroke of karma, or the clever hand of screenwriter Mike White: Dewey finds his level, becoming the substitute teacher for a class of sixth graders. Of course, they know more than he does about every subject except rock (appalling, the ignorance of these 11-year-olds when it comes to arena bands of the 1970s); and when he forms them, on the sly, into a group of their own, they play and sing better than he does. No matter. Dewey has rock-and-roll attitude–and in the lovely but improbable view of School of Rock, that’s what’s most lacking in today’s youth.

Richard Linklater directed, bringing to Dewey the same amused sympathy with which he’s chronicled the lives of the Dazed and Confused. Linklater is also an experimenter (as he’s proved throughout his career, from Slacker through Waking Life); and he’s satisfied this side of his nature, too, despite the present picture’s conventional form. For School of Rock, Linklater actually put together a band made up of 10- and 11-year-olds. (Only the drummer was a ringer; he was 13.) It’s predictable that when the kids at last perform in the story’s Battle of the Bands, everybody onscreen will cheer. What’s unforeseen about School of Rock, and wonderful, is that you feel like joining in.

In June 2000, a young man named Sandro do Nascimento tried to rob the passengers on a bus in Rio de Janeiro, was interrupted by the police and took eleven passengers hostage. A SWAT team quickly showed up, followed by TV crews and crowds of onlookers. The ensuing standoff became a public event, comparable perhaps to the police chase after O.J. Simpson’s van, only far more significant and horrifying. For one thing, Sandro, unlike O.J., represented a very large class of citizens: Brazil’s homeless kids. For another thing, the deaths took place on camera.

José Padilha’s riveting, comprehensive, deeply thoughtful documentary Bus 174 covers not only the incident itself but also the biography of Sandro do Nascimento (a brief and appalling tale), the lives of Rio’s street kids, the sociology of the police and the grim realities of the penal system. In terms of sheer legwork, what Padilha achieved is astonishing. He obtained interviews with Sandro’s family, surviving hostages, SWAT team members, journalists and informed commentators–everyone except the government officials who intervened so disastrously in the standoff. What’s more, Padilha brought together a variety of news footage of the event, which lets you see and hear Sandro for yourself.

He was 21 at the time and looked about 40. Ragged, coked up and starved-looking, he was unmistakably desperate in these last hours of his life but was just as clearly at a high pitch of excitement. Now that he’d inadvertently got everyone’s attention, this man who’d been kept voiceless and invisible was able to command the public stage. As Padilha notes, the price of the performance was awful–and so long as Brazil doesn’t change, you may expect it to be paid again.

Bus 174 is now playing in New York City at Film Forum and will go into national release in November.