DERAILED — * 1/2 — Clive Owen, Jennifer Aniston, Vincent Cassel; rated R (violence, profanity, sex).

"Derailed" announces Jennifer Aniston's departure into a seductress role by introducing her gams before her face. As her character rides a commuter train, director Mikael Hafstrom focuses on Aniston's high heels and her calves, clad in dark stockings as opaque as the film's twists are transparent.

Aniston and Clive Owen have perpetrated a deception by appearing in this picture. The presence of these marquee stars, along with a sleek production design, suggest this story of would-be adulterers caught in a blackmail plot will be of high quality. But "Derailed" is ugly and predictable when it should be sexy and sophisticated.

As unhappily married financial analyst Lucinda, who meets unhappily married ad executive Charles (Owen) on the train, Aniston at least shows she can play against type. Less emotionally accessible than Aniston's previous characters, Lucinda is flirtatious but cool in interacting with Charles, as if careful to maintain the upper hand.

Owen doesn't yet have a type to play against, but he does have a signature expression: morose. He veers from this expression at least four times in the film, a few times approximating a grin.

His character never engenders much sympathy, because he's straying from a lovely schoolteacher wife (Melissa George, from "The Amityville Horror") with whom he's raising an ill daughter (Addison Timlin) in desperate need of a new kidney. Charles and his wife have mortgaged their warm, well-appointed suburban home so they can save for an experimental anti-rejection drug for the girl. This guy brings a lot of baggage with him into an affair.

Lucinda's circumstances are less complicated, since her own daughter is healthy and her husband preoccupied with golf. Still, she appears to have the guiltier conscience of the two.

As Lucinda and Charles ride through the rain-soaked streets of Chicago looking for a hotel for their first assignation, Lucinda orders the cab to stop, telling Charles she can't go through with it. But the taxi has stopped near a tawdry hotel that looks like it would rent rooms by the hour.

Apparently satisfied they have found the scuzziest, most noir location in Illinois, the pair begin removing their clothes. They are nearly in flagrante before a robber (Vincent Cassel) bursts in and takes them out of flagrante. The moment is so stagy that Charles and Lucinda seem to be the subjects of an adulterers' version of "Punk'd." But it's the audience getting played.

Rapper RZA, playing a pal of Charles' from work, seems far more vivid and lifelike than other actors. Perhaps that's because he's one of the few Americans here besides Aniston, and therefore doesn't have to fight his natural accent the way Frenchman Cassel, Englishman Owen, Aussie George and Scotsman Tom Conti (as Charles' boss) do.

Written for the screen by Stuart Beattie ("Collateral") from a book by James Siegel, "Derailed" most closely resembles moralistic American films of the 1980s and 1990s, most notably "Fatal Attraction," that chastised characters for their cushy Yuppie lifestyles as much as for their sexual indiscretions.

"Derailed" is rated R for strong disturbing violence, language and some sexuality. Running time: 100 minutes.