“Up and Down,” a new film written and directed by popular Czech filmmaker Jan Hrebejk — popular, at least, in the Czech Republic and with foreign film fanatics — is intended to be a tragicomic satire along the lines of “The Royal Tenenbaums.” Yet much of the film is delivered in such an absurd and fanciful manner that the outlandishness nearly cancels out the seriousness, if not Hrebejk’s intended message. On the flip side, many supposedly funny moments are hampered by uneven solemnity. Nevertheless, “Up and Down” is emotionally stirring and exceptionally satisfying as an intimate family melodrama loaded with biting commentary on modern-day Prague.

Hrebejk garnered critical kudos, and a great deal of popular attention, for his Holocaust-based “Divided We Fall” (2000). Like “Life Is Beautiful,” the film was a black comedy that suffered from being neither funny nor sufficiently moving. “Up and Down” is more successful, and as a result is more believable and more artful.

The movie’s opening sequence sets the tone for the politically charged melodrama that follows. In the middle of the night, two smugglers transporting illegal immigrants across the border into the Czech Republic chaotically force everyone out into the dark countryside. Later they discover that they’ve left a couple’s baby in the truck, which they sell at their seedy pawn shop to an emotionally unstable and barren woman named Mila (Natasa Burger).

But the baby threatens to get Mila’s husband Franta (Jiri Machacek) into trouble with the police. On probation for some unspecified violence he committed as a rowdy soccer fan, the couple isn’t allowed to adopt the baby. As if this threat weren’t trouble enough, Franta’s soccer hoodlum friends refuse to associate with him because the baby is Indian.

Intersecting with these two storylines — which suffer from relatively exaggerated acting and plot twists that border on the unbelievable — is a third that is by far the most successful strand of the film. Halfway through the film we meet Martin Horecky (Petr Forman, the son of celebrated director Milos Forman), a Czech who emigrated to Australia after his family broke apart, having fallen from the Czech upper class. This plot is the emotional center of “Up and Down,” providing most of the film’s poignancy and best social commentary.

Martin returns to Prague to visit his cancer-stricken father Otto, a once-successful university professor. The family reunion is edgy, to say the least; Otto abandoned Martin’s mother Vera for his much younger mistress Hana (Ingrid Timkova), who was once Martin’s girlfriend. Though the story might sound like fodder for a soap opera, Hrebejk’s sympathetic characters brilliantly carry the segment.

The method with which Hrebejk unites and separates the film’s storylines is reminiscent of Robert Altman’s great ensemble dramas, especially of P.T. Anderson’s 1999 epic “Magnolia.” But the transitions in “Up and Down” are not nearly as seamless as Altman’s editing. The dichotomy between the over-the-top absurdities of Mila and Franta, and the far more believable family drama of Martin, can be jarring. Yet the film’s most dramatic moments provide a glimpse into a great film buried beneath its contradictions.

A lengthy scene in the middle of the film, which unites Martin’s extended family in one tense luncheon, is a masterpiece of controlled chaos. The discussion centers not only on their family troubles, but on the struggle of the Czech old guard — Otto and Vera — in maintaining their social status despite decreasing fortunes and swarms of migrants. Their bigoted attitudes toward immigrants collide against Hana’s liberalism in a heated shouting match. The far more reasonable younger generation, Martin and his half-sister Lenka, receive the bulk of the audience’s sympathy as they resist their strong-minded parents.

Hrebejk allows his characters to engage in histrionics — throughout the film, he exhibits little subtlety or restraint with his dialogue — yet the climactic scene remains completely engrossing and believable. It doesn’t hurt that he’s working with very fine actors. The scene is emotionally fraught melodrama without sentimentalization or stereotype, and it is by far the most successful of the film.

Hrebejk, who has been making movies since the late 1980s, possesses many gifts as a writer-director: Colorful and interesting characters, fluid pacing and a surreal but beautiful visual style. But the film, like “Divided We Fall,” is hampered by unnecessarily outlandish and only moderately successful comedy. If Hrebejk abandons his tendencies toward comedy in favor of hard-hitting drama, he is certainly capable of making a masterpiece.