"Photos are only taken of happy moments," says Robin Williams' decidedly unhappy character in One Hour Photo. It's one of those observations that's so obvious it usually flies completely under our radar, and Williams' character backs it up by citing the endless supply of snapshots documenting familial bonding, love, reunions, celebrations, personal successes, holiday gatherings and other ostensibly joyous occasions. Contrast that with the number of times you've leafed through someone's photo album (Diane Arbus' doesn't count) and been overwhelmed with shots of funerals, divorce proceedings, people in pain or other similarly unpleasant imagery.

Oddly enough, the exact opposite holds true for movies — at least for independent movies. Indie films, particularly films from first-time directors, all too frequently concern themselves with subject matter of a distinctly dark and unsavory nature. It's almost de rigeur for many of these fledging filmmakers, as if driven by the need to be "different" and bound by some over-simplistic view equating Hollywood with Sweetness and Light, to feel compelled to beat a path directly to the dark side.

There are way too many cases in point to mention, but allow me to just recap a few of the year's biggest (although not necessarily best) indie success stories. We had In the Bedroom, in which a son is murdered and then revenge is methodically carried out by the distraught parents. Then there was The Good Girl, an ostensible comedy in which an unhappy Texas housewife sleeps with a manic-depressive youngster and then ponders poisoning him. And let's not forget Tadpole, a popular riff on The Graduate featuring a know-it-all high schooler who sleeps with his stepmother's best friend, even though the one he's really hot for is stepmom herself.

Even more to the point, and closer to the heart of darkness, two of the year's better American indies are both films about deeply, dangerously disturbed individuals: Bill Paxton's serial killer flick Frailty, and now writer/director Mark Romanek's sophomore effort, One Hour Photo.

Like Fraility, Romanek's One Hour Photo is the story of a ticking human time bomb told from the perspective of the time bomb himself. A cool, crisply elegant horror story told in flashback, we see our protagonist in handcuffs from pretty much the first frame and are given the unmistakable impression that this guy is definitely somehow off, and that he's done something terribly wrong. From that starting point, a cloud of uneasiness hangs over the entire movie, creeping us out at every turn as we play along with its stomach-knotting game, waiting for this quiet, nondescript man to do the unspeakably awful thing that put him in this situation.

Again as in Frailty, we have a central character in One Hour Photo whose very ordinariness is a cover for the demons lurking within. Robin Williams is utterly self-effacing as Sy Parish, a mousy little man better known as Sy the Photo Guy. He's a longtime employee in the photo-developing department at a Wal-Mart-type chain, a job he treats with something approaching reverence. He takes enormous pride in his work and, as he explains more than once, processes his customers' photos as if they were his own. And in a very real (and very creepy) sense, as the movie eventually makes clear, they are his own.

Beyond his work, Sy has very little in the way of a life. He's basically a ghost — a pale, bland figure who barely registers on those around him. With his clear-framed glasses, light, thinning hair and polyester-blend wardrobe in an endless variety of washed-out gray, Sy seems to barely exist. He goes to work, eats at the same place every day, and goes home to a sparsely furnished apartment where he lives alone, save for the pet hamster running endless circles in his little cage, just like Sy.

Sy has a secret, though, and it's a whopper that provides him with the one source of pleasure in his sad little life. In lieu of an actual existence of his own, Sy has formed a covert and entirely one-way relationship with one of the families for whom he processes pictures. Unknown to the Yorkin brood — mama Nina, papa David and little Jake — their friendly, forgettable photo guy has become completely obsessed with them, even going so far as to literally wallpaper his apartment with the duplicate prints of their family snapshots that he's been secretly running off for years.

Sy seems to regard the Yorkins as some sort of ideal of happiness, a perfect family unit of which, at times, he even appears to regard himself as a member. At one point he even shows a picture of the Yorkin's son to a waitress and claims to be the boy's uncle. That's only the tip of the iceberg regarding Sy's penchant for manufacturing an alternate existence for himself out of the lives and memories of others; he later informs the same waitress that the old photo of an anonymous woman he's just purchased at a flea market is of his mother.

Sy prefers images of reality to reality itself (a phenomenon perhaps not so far removed from what many of us experience these days), and his perceptions of life are completely colored by the information he feels is communicated in those photographic images. When Sy feels the Yorkins are happy, then they become his happy family, and he's happy too. But when Sy starts to sense trouble in paradise, the movie begins taking a series of increasingly ugly turns that set everyone's life spinning out of control.

One Hour Photo is a disturbing little movie, and the most disturbing thing about it is the manner in which it illustrates how easy it is for the ordinary to transform gradually, almost imperceptibly, into the dangerously malignant. The film is all about the crossing of lines and how true horror lies in the minute shifting of perspectives, the changing of vantage points by which the small, normal moments becomes distorted, gross and hateful.

Williams is understated and excellent throughout — all hard-set features and awkward, uptight body language — in a role that might easily have come off as too close for comfort to his recent turn in Insomnia. His dull, middle-aged character is both ominous and pitiable, and watching him lavish attention on the Yorkin's 9-year-old son and, in one memorable moment, walking alone with him in an isolated area, becomes a chilling sight. That we're all currently living in a climate poisoned by the fear of child abductions doubtless makes watching the scene play out all the more disturbing.

Sy, as he himself tells us, is an admirer of details, of the "small things" that make life interesting, and so is the film. One Hour Photo operates mostly on a slow burn, with a style that's cold and crisp and intentionally a little flat and off-center, just so we know that this isn't your typical Hollywood production. Through sure attention to detail and rhythm, the movie manages to be thoroughly engaging for its first 40 minutes, even as the plot trudges along like molasses. When things begin to kick into hyperdrive around the midpoint, the film loses a bit of its uniqueness, but by then we're hooked and it doesn't matter. Things go from bad to worse, story-wise, with the bulk of the film's most intense moments occurring in its final act. In the end, there's a very odd twist sure to play havoc with your stomach, nerves and maybe even your emotions.

It's not exactly profound stuff, but it's the kind of movie that's bound to make you think twice the next time you bring in photographs to be developed. And that's maybe the best thing one could say about One Hour Photo: It's a terrific 98-minute advertisement for digital cameras.