Did you hear the one about the young Marine and the mentally ill movie star?

It sounds like a joke but that is indeed what the continually eccentric "Stateside" happens to be about. A film reflecting its writer-director's own course through life, it's so unexpected and unpredictable and so full of tiny grace notes that its ultimate collapse seems almost irrelevant.

The time is 1980, and the location is a posh Connecticut suburb of New York, where young ne'er-do-well Mark Deloach (Jonathan Tucker) is busy destroying his life. If you have ever lived in a posh suburb, you'll recognize him immediately: First cousin of Holden Caulfield and blood brother of Igby Slocumb, the title character in 2002's "Igby Goes Down," he's the extra-bright rich kid who can't keep his hand -- or his life -- out of the fire. As we watch, Deloach, an alcoholic at 18, drunkenly engineers the prank kidnapping of a girl who is making out with a pal, then rams his sports car into two others. For a terrible moment it looks like he's killed everybody, but he's only maimed them for life. Talk about the luck. Rather than face jail, he is, thanks to the connections and importunings of his dad (Joe Mantegna), consigned to the United States Marine Corps.

Something like this evidently happened to the writer-director, Reverge Anselmo, who logged corps time as well, and in some sense it's a thank-you note to the institution that saved his life by treating him like a maggot in an unlovely location called Parris Island, S.C., during an unlovely ordeal called basic recruit training.

Anselmo goes to some lengths to dramatize the unpleasant adventure of making the corps, knowing of course that in doing so, he's up against some movie icons. The part of the drill sergeant, that towering image of theatricalized machismo, has been played by, among others, John Wayne, Clint Eastwood, Louis Gossett Jr., Jack Webb . . . but perhaps most memorably by R. Lee Ermey in "Full Metal Jacket," a figure of such force and charisma, perhaps drawing its verisimilitude from the fact that Ermey was an actual retired Marine drill instructor.

Faced with such imposing company, Anselmo chooses to underplay. The role goes to Val Kilmer, a noted eccentric, and Kilmer's DI isn't one of those towering star-brutes of sheer animal magnetism and utter capability so much as a quietly insistent prodder. He hardly spits at all when he talks, and he never comes up with the flamboyant constructs, typical of sergeants of any service or century, that always sound like Homeric verse drawn through a sieve of 110-proof high-Baptist blasphemy and delivered in the accents of someone who clearly knows how to kill, skin and stew a squirrel. But Kilmer has weight and gravitas in the part, and he doesn't ham it up. You believe him.

This is no gigantic production. Unlike Kubrick's Parris Island in "Full Metal Jacket," which was filmed on a converted Royal Air Force base, Anselmo gets a surprising feel of authenticity out of a few acres of swamp, a single barrack, 35 sets of utilities and 35 reasonably gung-ho actors playing Platoon 2021. More important, he gets military culture fairly believably, a kind of tough-love in which the boys are broken but not too deeply and then helped to heal and reassemble themselves in the form of a new man, a United States Marine. Anselmo pulls no punches in the making of Marines, but he's not shocked or out to "expose" anything, either. He's proud he made it through and he's proud his young hero does, too.

In the movie's other half, things are somewhat more amorphous. When, on leave, Deloach goes to visit the young woman who was injured in the auto crash, not in the hospital but in a mental hospital (her mother, after the accident, discovered a hidden sex diary and decided her daughter needed help, or at least a curfew), he meets her roommate, a young actress named Dori Lawrence (Rachael Leigh Cook), and they promptly fall in love.

You would think that the Marine Corps-Showbiz tension would dominate the relationship, but it doesn't. Dori Lawrence, besides being some sort of ex-child star, is also schizophrenic, and Cook does an excellent job in charting her mood swings, her occasional drug reactions (slurry voice, sluggishness), her fragility, her impetuousness. I was surprised by how believable the material became, given its overall improbability.

Basically Anselmo tracks between the two stories, as Marine training alternates with seize-the-day madcap liberties set in a well-evoked early '80s, but each story line heads toward catastrophe. Deloach will end up in a barracks in Beirut when a truckful of explosives go off (the first few seconds of the film disclose this) and Dori, for all the magic of Deloach's love, will get worse, not better.

Both those story lines work; it's the movie's predictable ending that doesn't, and it doesn't really answer any of the questions the film has raised. Still, Anselmo has a talent for evoking a lot on a low budget and for creating believable characters in circumstances that seem unbelievable. He's a director to be watched.

Stateside (95 minutes, at area theaters) is rated R for language, sexual content and underage drinking.

Jonathan Tucker is a Marine recruit with a lot to learn.Jonathan Tucker as the Marine and Rachael Leigh Cook as the schizophrenic actress: Two story lines that meet and fall in love but ultimately end badly.