“Collateral” is a great-looking movie, with that glistening metallic sheen that all of director Michael Mann’s films have boasted. In his hands–and those of ace cinematographers Dion Beebe and Paul Cameron–even the usually hokey helicopter shots looking directly down on nighttime Los Angeles as transitional devices delight the eye–something that’s especially remarkable given that much of the picture was shot on high-definition video. David Wasco’s production design is excellent as well; indeed, visually the picture is a constant delight. The problem with “Collateral” is that while engaging the senses, it starves the brain. It’s based on a premise that’s inherently silly, adds to it a whole series of implausibilities, and then winds up with a final act that offers lots of action but makes absolutely no sense. The picture is all flash and no light–but the flash is brilliant.

The idea behind Stuart Beattie’s script is a simple, and not very realistic, one: an L.A. cab is highjacked for a night by a visiting hit-man, who forces the driver to take him to the locations of each of his five assigned targets. (The premise is made even less plausible by a suggestion later in the picture that it’s not the first time the killer has used the same MO.) The cabbie, Max Duroscher (Jamie Foxx), is an intensely organized veteran who has routes timed down to the minute but dreams of the day when he’ll be able to run his own limo company; he’s also just dropped off a beautiful lawyer named Annie (Jada Pinkett Smith), who was so taken by his attitude and personality that she slipped him her card, and so has something potentially romantic to live for. The hit-man, simply named Vincent (Tom Cruise), is a slick, steely-eyed type with formidable skills in blasting people away and a tendency to expound cynically on modern society. As the mission proceeds, they pick up some tails–local cops (Mark Ruffalo and Peter Berg most notable among them) and drug task-force feds (headed by Bruce McGill). The reluctant cabbie also attempts to escape from time to time, and on one occasion he’s forced by Vincent to impersonate the killer in order to retrieve some back-up data on the job from his employer, a serpentine Latino named Felix (Javier Bardem). The duo also runs into some street toughs, whom Vincent disposes of handily, and even takes some time off to visit Max’s hospitalized mother (Irma P. Hall) and a jazz bar whose trumpeter-owner (Barry Shabaka Henley) regales them with reminiscences of the night Myles Davis came by to jam. But the meat of the evening, of course, lies in the successive killings, which begin with an abrupt fall from a third-story window that clues poor Max in on what Vincent’s about and all involve some striking set-piece that Mann stages with his customary icy precision. (The most elaborate is a highly complex shoot-out in a crowded nightclub, where Vincent faces off against an army of bodyguards and pursuing cops in order to get his man, while writhing patrons surround the action.) And, of course, there’s an elaborate concluding chase, which starts on the top floor of an office building and continues onto the L.A. mass transit system.

“Collateral” is a very efficiently manufactured product. It may not be remotely credible (especially in the final act, which involves a killing that–in view of those that have preceded it–is entirely superfluous), and the coincidence that connects the beginning with the close is a hole wide enough to drive the cab through. But the level of technical craftsmanship is so high, and Mann’s skill so great, that it chugs along smoothly anyway, like a well-oiled machine. The comparison to a mechanical contraption is appropriate, though, because there’s barely glimmer of humanity in it–indeed, Vincent’s periodic rants on the dehumanization of life in L.A. (he tells a story about a guy whose death goes completely unnoticed) have a self-referential twist in this context. The characters all seem like sketches, too. Cruise is about as robotic as any of the foes that Jada’s husband Will faced in his recent summer blockbuster; with his close-cropped, bleached hair, granite demeanor and colorless wardrobe, he’s as grimly grey as they were, too. It’s certainly an effective turn, but one without much range. Foxx tries to bring shading to the hapless Max, but he never gets much beyond the surface; and his suddenly apt role-playing in his scene with Felix impresses as nothing more than a poorly-conceived stunt (one that’s also unnecessary, if you accept a hint about Vincent’s previous activities dropped later in the film). Since this is essentially a two-hander, few others in the cast shine. The exceptions are Hensley and Bardem, who make their brief appearances count (it helps that they’re given some of the jazziest, loosest dialogue in the whole script). Smith seems a mite overparted, while the only really notable aspect of Ruffalo’s sturdy but anonymous turn is how different he looks with his usually tousled hair slicked back. Hall comes on much too strong, but the fault lies more with the over-the-top writing for her character than the actress, while Berg and McGill make virtually no impression at all.

As a cinematic exercise rather than a movie, “Collateral” is impressive, in the same way that Alfred Hitchcock’s “Lifeboat” or Joel Schumacher’s “Phone Booth” were. But in terms of plot it’s less satisfying than the former and only slighter better than the latter. Ultimately Mann’s film feels like a $100 million retread of “The Hitcher,” but though it’s bigger and showier than that odd little horror film, its attempt to add some existential commentary to the roadway mayhem doesn’t work nearly as well.