IT REALLY happened. That's the point of Louis Malle's tragic "Au Revoir Les Enfants" ("Goodbye, Children") and late in the movie, a tragic and true incident draws the tears. But Malle drums his stylistic fingers until that moment, content with vignettes that are minimally involving.

The vignettes take place in a French Catholic boarding school during the Nazi occupation. For 12-year-old student Lucien (Gaspard Manesse), 1944 isn't going to be just another semester of Latin gerundives, Hail Marys and shortsheeting. He'll befriend new boy Jean Bonnet, a bright lad with a heavy secret. To say more would give it away.

Malle's recall of his own youth is veiled by time. Looking back forty-odd years, he sees "Au Revoir" as an evocative slide show of faces, buildings, rows of beds and classrooms. Thus the movie's surface is exquisitely mounted by Malle, he of the formidable resume ("Black Moon," "Murmur of the Heart," "Lacombe, Lucien," the American-produced "Pretty Baby" and "Atlantic City").

But his screenplay says "Au revoir" to deep characterization, even of such key players as school principal Pe`re Jean (Philippe Morier-Genoud), a courageous man undertaking a risky venture. And though young Jean Bonnet's relationship with Lucien is crucial, it remains unexplored: They meet. They talk. They halt, unsure of each other. The chemistry between them never quite happens, and Malle meanwhile seems too busy with the overview, the look, the flow.

Manesse's Lucien has arresting, cute-boy features, but he's really a wide-eyed, moving prop, reciting his tables, wetting his bed. Raphae l Fejto 's Jean, in turn, is a pathetic kid who keeps his distance from everybody -- including us.

Much of Malle's final impact comes from the lean diet he's imposed up to then. You're starving to cry. There are exceptions along the way, though -- among them a scene in which Lucien and Jean, playing a game of military hide and seek, get lost among rocks in the woods, and another, perhaps the best of the movie, in which an old gentleman regular at a restaurant is asked to leave by a French collaborator, only to be invited back by a sympathetic Nazi officer.

By many other directors' standards, "Au Revoir" would be a major achievement. But Malle has reached higher. If he'd made his childhood movie earlier in his career -- when he didn't have the sense to be so dispassionate -- it might have packed a meatier punch. Now it's just a deftly aimed poke.

AU REVOIR LES ENFANTS (PG) --

At the Key.