''Derailed" is a tawdry, predictable hunk of movie headcheese, and I still had a pretty good time with it. As I walked out of the movie theater, though, I reminded myself that critics see these things for free and that if I'd paid $9 plus Goobers and Coke like everybody else, I'd doubtless feel rooked. The issue here is return on investment, and the ROI on this businesslike but not very bright little thriller starring Clive Owen and Jennifer Aniston is minimal, if not in the red. If you stumble across it at Blockbuster, though, or, better yet, if you turn on pay cable and it's just starting, power down your brain cells, get a bowl of Chubby Hubby, and settle in.
The plot is as pulpy as the airport novel from whence it came. Frazzled suburban family man Charles Schine (Owen), a Chicago ad exec with a distant wife (Melissa George) and diabetic teen daughter (Addison Timlin), flirts with a fellow commuter on the train. She's a financial adviser named Lucinda Harris (Aniston), and she has legs a middle-age man might focus on while pretending to read The Wall Street Journal. She also has a cool exterior that hints at a softer core; this constitutes the one lonely nuance of Aniston's performance in ''Derailed," and, thespic duties thus dispatched, the actress is free to look dazed while contemplating visions of Angelina Jolie in a wood chipper.
Charles and Lucinda's coy banter leads to lunches, which lead to a dinner, which leads to an erotically charged cab ride, which leads to a hotel . . . and now I have to leave you at the doorstep, because there are surprises afoot. To quote Charles as he helps his daughter with her book report in the film's opening scene, ''The author seduces the reader by twisting the narrative so you never know what's coming next." (Yes, it's the first movie script written in yellow Hi-liter.) If you're willing to play as dumb as the characters, though, you stand to be shocked when ''Derailed" takes a sudden turn for the ugly.
The rest of us are just glad Vincent Cassel has turned up, dripping merry French psychosis. The bad-boy actor (''Irreversible," ''Ocean's Twelve") plays Philippe Laroche, an amoral street thug set on terrorizing Lucinda and blackmailing Charles into emptying his bank account. The neat trick of any Cassel performance is that it's perched on the knife edge of gentility and homicide, and so it is here: Philippe can beat Charles until his ears bleed in one scene and in the next be sitting in Charles's home in a trim suit, charming his victim's wife and daughter with naughty Gallic wit. When Charles comes home, the two women look at him like he's the plumber.
Owen walks through the film like a very good-looking two-by-four, and I guess that's a sensible approach; he knows he'll outclass the material if he's not careful. So the juice in ''Derailed" is in the supporting roles, including RZA as Winston, the office mailboy and former jailbird who becomes Charles's unlikely protector on the mean streets of Chicago. The rapper/producer/composer gives his character a sweet smile and dead eyes.
After enough implausibilities and plot twists have piled up, ''Derailed" backs itself into a nifty little scene where everyone's gun points at everyone else and you wait for the first shot to start the pinballs flying. If director Mikael Hafstrom had given the whole movie the stupid, unrepentant energy of that scene, we might have had a fine piece of B-movie sleaze. As it is, ''Derailed" suggests classic film noirs like 1945's ''Scarlet Street" (just out on DVD, and talk about return on investment) stripped down to pure functionality. Sometimes that's enough, but only on TV and only when no one else is awake.
Ty Burr can be reached at firstname.lastname@example.org.