David Duchovny's a smart, talented fellow who wrote and directed a few "X-Files" episodes, so you'd trust him with a small independent film. Yet here's "House of D," which he wrote and directed, and which he nearly ruins by including not just a mentally handicapped adult character, but a mentally handicapped adult character played by ROBIN WILLIAMS.

If the very thought of Robin Williams playing a sagacious retard -- because of course this is the sort of mentally challenged man who is far wiser than his peers -- doesn't make you cringe, let me help you out. Consider these previous films where he played a Wise Man-Child Who Shows Everyone The Way: "Good Morning, Vietnam," "Dead Poets Society," "The Fisher King," "Hook," "Jack," "Patch Adams," "Jakob the Liar," "Bicentennial Man," and heck, why not go back to "Mork & Mindy"?

Wincing yet? Here's some more. In "House of D," Williams wears a special dental device to give him Retard Mouth. And sometimes the character he plays, a 41-year-old mentally challenged man, gets an obvious erection! He can't help it; he's retarded!

Does Williams mug and cavort and behave like a monkey? Yes. Does his character say things that are far too clever and quick-witted even for most regular people, let alone mentally challenged ones? Indeed he does.

I know what you're thinking, but the answer is no, I will not kill you now. Because lucky for us, Williams is not the central figure in "House of D," and though he grates when he is on screen, the film is otherwise a passable, even poignant, coming-of-age story.

The main character is Tommy Washaw (Anton Yelchin), on the brink of his 13th birthday and living with his mother (Tea Leoni) in Greenwich Village in 1973. His father died not long ago, and Mom has been at her wit's end ever since, smoking heavily and taking the occasional one-sedative-too-many. She and Tommy are reliant upon each other's willingness to occasionally switch roles, with him putting her to bed and then sleeping on the floor underneath so he knows she's safe. They haven't quite reached the Oedipal Complex, but they can see it from the freeway.

Tommy has an after-school job as a bicycle messenger, delivering meat for a local butcher, with Pappass (the aforementioned Williams) as his partner and best friend. They have a fine time horsing around and cracking jokes -- Pappass is also the janitor at Tommy's Catholic school -- and Tommy does his best to make Pappass feel like part of the gang. In the meantime, they're saving up their money for a brand new bicycle they want.

But then Tommy starts to grow up. He meets a girl he likes, Melissa (Zelda Williams, Robin's daughter), and wants to know how to woo her. Pappass is useless in that regard, so Tommy turns to an unlikely source: The Women's House of Detention. This medium-security prison is in an old stone building right in the middle of the Village, with inmates able to carry on conversations with passersby on the street below. (The House of D really existed like that until 1974. As you might expect, neighbors eventually complained about the loud conversations being conducted at all hours of the night between inmates and their pimps, lovers and innocent bystanders.)

Tommy winds up conversing with Lady Bernadette (Erykah Badu), who dispenses obvious advice about girls. (If a 12-year-old girl teases you, it's because she LIKES you! Duh, Tommy. Duh.) Tommy takes her advice and things go smoothly, until an incident regarding the theft of a bicycle causes everything to go downhill.

The entire story is framed with scenes set in the present day, where a grownup Tommy (played by Duchovny) is living in France and explaining to his French wife where he came from and what happened when he was 13. The last 20 minutes of the film are entirely set in the present, as Tommy finds he must return to New York to wrap up some loose ends. (Yes, friends, not only does Robin Williams play a retarded man with fake teeth, but and he also gets to wear old-age makeup. It's the schmaltz trifecta!)

But the adult Tommy isn't nearly as interesting as the 13-year-old one, partly because Duchovny isn't as engaging an actor as young Anton Yelchin, and partly because the problems facing the adolescent Tommy are much more relatable than the vague ones the grownup Tommy has. (He has to go back to New York ... why?) Yelchin, a mostly unknown actor (he's a regular on the "Huff" TV series), gives a very respectable performance here, covering a wide range of emotions believably. A movie about him and his mother, with no Williams or Duchovny, would have been infinitely better.

THE DVD

VIDEO: It's presented in anamorphic widescreen (1.85:1), and the transfer is smooth. Duchovny pulls a few nice-looking visual tricks here and there, but mostly the focus is on the earth tones of the early '70s, which come through as crisply as they are meant to.

There are optional English subtitles, useful especially when Duchovny is mumbling (er, speaking).

AUDIO: The audio comes in either 5.1 Dolby Digital or 2.0 Dolby Digital. The film is not heavy on music or sound effects, but when they are employed, they sound excellent.

EXTRAS: You know how David Duchovny has that really flat monotone voice? Would you like to hear it for 97 minutes straight? Well, you're in luck, because he provides a commentary. That said, he's always been a glib, deadpan sort of fellow, and while his commentary focuses too much on mundane specifics (where this was shot, who was kind enough to provide that prop, etc.), he cracks a few amusing jokes and gives a few interesting side notes, too.

There is an "alternate ending" that doesn't change anything but simply adds a little bit of extra info about what happened to the real-life House of Detention. Meh.

Another "meh" for the four deleted scenes. One provides info that we wound up getting in a later scene instead, two are merely (barely) extended versions of existing scenes, and one would have made the last act even sappier than it is, so thank goodness it was cut.

"Building the House of D" is an 11-minute featurette emphasizing on-set interviews with cast members interspersed with moments from the film. It is fairly standard, as these things go.

The "All Access Festival Pass" is 14 minutes of Duchovny's Q-and-A after a screening of the film at the Santa Barbara Film Festival. There are no special revelations or insights, but Duchovny is his usual wry self.

Probably the most useless featurette is "The Old Neighborhood," which is three minutes of clips from the film that are set in authentic New York locales, interspersed with a few seconds of behind-the-scenes footage. It's not about how they found the locations, or what the locations' real stories are; it's just clips from the film that happen to INVOLVE the locations. Whoopee.

IN SUMMARY

This is a passable movie that could have been much better, were it not for Duchovny including himself and Williams. But if you are a fan of Williams' prior "look-how-wise-the-buffoon-is" roles, you will probably not mind him here, which means the movie might entertain you. Otherwise, it's barely worth a rental.