"One Hour Photo," of course, has grown much of its hype out of Robin Williams focused, laugh-free performance, and from the opening scenes it is easy to tell why. Williams, who was so good in a similar role in the recent "Insomnia," has utterly nailed this part. With short, balding white hair and a happy external demeanor that can't quite mask the pain and loneliness he harbors within, Williams has so convincingly embodied his character with nuanced flavor and subtle power that, as in "Insomnia," he reminds us of just how brilliant an actor he can be with the right script.

At the oppressively pallid SavMart, a WalMart clone in every way except for its stringent tidiness, Sy Parrish (Robin Williams) dutifully heads the one-hour photo shop, developing each picture with the sort of care and perfectionism one might develop their own rolls. The only difference is, Sy has no pictures of his own to take. Bereft of any family or even a single friend, he works hard at his low-paying job and then comes home to a bleak, empty apartment and watches television.

His favorite customers at SavMart are the Yorkin family--parents Nina (Connie Nielsen) and Will (Michael Vartan) and 9-year-old son Jakob (Dylan Smith). For the Yorkins, who have been developing all of their joy-filled photos at SavMart since before Jakob was born, Sy is but a friendly acquaintance whom they see a few times each year. What they don't know is that Sy has been obsessed with them for some time, living through them by secretly making extra prints of all of their photos and pasting them to his apartment walls. In his delusional fantasy world, he even thinks of himself as Jakob's Uncle Sy. His idealistic view of the Yorkins finally comes crashing down when he discovers adulterous photos of Will with another woman. For Sy, whose sanity is already wavering closely to the edge, this is heinously unacceptable behavior that must be corrected.

Writer-director Mark Romanek and cinematographer Jeff Cronenweth have handed "One Hour Photo" a sparse and sterile visual style that calls to mind Stanley Kubrick, offsetting Sy's mental anguish with effective aplomb. Likewise, a large crack Sy gets early on in his car's windshield hovers threateningly over the proceedings, symbolically representing his instability and reminding him of what a nobody he is to everyone in his life. These small, but significant details in Romanek's solid storytelling approach lends further weight to the film's portrait of a well-meaning, middle-aged man who has become unglued by his own demons and an unfair society.

Because Robin Williams' haunting performance is so on-target, and the movie weaves an increasingly chilling spell, it is a little disappointing that some of the less thought-out plot developments rise so evidently to the forefront. When Sy's heartless boss (Gary Cole) correctly accuses him of giving Jakob a disposable camera for free on his birthday, one must wonder how he could have possibly found out about such a thing. Most glaring of all, though, is an ending that wrongfully feels the need to explain away Sy's past and his motives, when they should have remained cryptic and open-ended for the audience. Going for such an easy answer is unconvincing, especially when the character has already been given the sort of depth Williams entombs Sy with.

The final ten minutes notwithstanding, "One Hour Photo" is a nightmarish portrait of the American Dream gone horribly awry. The supporting cast, especially Connie Nielsen (2000's "Gladiator") as the heartfelt Nina, is excellent, but they are overshadowed by Robin Williams, whose Oscar caliber turn deserves to be seen. A sort of modern suburban tragedy, the film digs deeply and touchingly into the psyche of a deranged human being who has nowhere to turn in life. For this feat alone, "One Hour Photo" is not easily forgotten.