Marc Forster’s overdue identity thriller “Stay” is a diverting if unsustainable piece of sub-De Palma psyche-out, with neat camera tricks and a passable sense of urban dread.

Kitted out in a tweed jacket and vest, Ewan McGregor plays Sam, a young New York psychiatrist treating an apocalyptically gloomy college student, Henry (Ryan Gosling). The kid is a puzzle, insisting he killed his parents (against apparent facts) and seemingly capable of clairvoyance. He stalks Sam, and the good doctor returns the favor, but the results of Sam’s investigations and his patient’s behavior resist rational explanation.

Also, Sam’s life seems to transform into Henry’s. Or something. It’s not entirely clear, but that is not necessary to appreciate the director’s methods. Syncopated editing, sharp angles, and creepy morph-melts from one scene to the next render New York a liquid continuum of confusing encounters and slick artifice – the hollow insides of a pair of ragged minds.

It is a reality with the malleable, synthetic look of “The Matrix” or playful avant-garde digital works like Michael Snow’s “Corpus Callosum.” Photocopy identical extras strut in the background, and deja vu scenes are endemic. When poor Mr. McGregor walks down a spiral staircase, it goes on, needless to say, without end.

And at this point I’m supposed to snipe that all this trickery is overdone, the plotting obvious, and the performances too serious. Frankly, I didn’t care (and, anyway, Mr. Gosling is rather good at death’s head moodiness). Obviously, “Stay” has done extensive time in the hell of test screenings and re-edits, haunted by the hollowness and indifference that is so often the result.

But there’s something to Mr. Forster’s attempt, whatever remains of it, at resisting a smooth viewing experience. Take those incomplete dissolves from one scene to the next. A character can be walking down the street and then, through the morphing of a background, be walking down a subway car. After an hour of this daisy-chaining, you begin to understand and long for the finality of the traditional cut and the relief of its clean demarcation of scenes, moods, and character focus.

It’s a successful little experiment in uncanny, subconscious dread, and, charitably viewed, part of a larger project. The authentic New York locations make the film’s dreamscape all the more disorienting with hyper real iconic locations like the Brooklyn Bridge or Pearl’s Diner downtown. And the psychopathologies of pre-gentrification old New York practically percolate in the background when Sam visits Henry’s old psychiatrist (a creepy Janeane Garofalo) in her ’60s Modernism-atrocity building.

But advertised as a vaguely supernatural thriller, “Stay” can’t help but be drawn into boring conversations: What’s going to happen next? How does it end? (And why is poor Naomi Watts, as Sam’s once-suicidal girlfriend, trapped in another fractured narrative?) In that sense, “Stay” is destined for the same fate as Jane Campion’s “In the Cut,” another atmospheric adventure in subjectivity that audiences rejected as a failed genre film.

“Stay” is nowhere near as ambitious, and even 98 minutes is long for this intriguing art project. Still, the film knows where to look when it comes to getting under the skin of urban dwellers. A scene near the end calls upon the wonderful parallel-universe thrill any straphanger will recognize: spotting, through the windows, the perfectly lit people on a neighboring express train. Likewise, for all the film’s stylistic loop-de-loops, you might well feel “Stay” is just passing you by.