"The Fast and the Furious" is one franchise that has never been good at naming its sequels—2003's "2 Fast 2 Furious" still makes me shudder—but the fourth installment, "Fast & Furious," takes the cake for sheer ineptitude. What brilliant studio exec thought it a good idea to strip the two uses of "the" from the original's title and call it a day? I digress. Chronologically fitting in between the second and third films in the series, "Fast & Furious" is notable only for bringing back the four central characters of its 2001 predecessor and upping the ante by stripping them of moral compasses. It's rather sad to think that questionable protagonists Dominic Toretto (Vin Diesel) and Brian O'Conner (Paul Walker) are five years older, and yet still haven't begun to grow or wise up. Their sense of right and wrong so skewed as to be unrecognizable, these platonic soul mates are now outright miscreants of criminal intent.

For half a decade, Dom and girlfriend Letty (Michelle Rodriguez) have been on the run, still boosting trucks but now doing it in exotic locations like the Dominican Republic. When tragedy strikes and someone close to him is murdered, Dom returns to his old stomping ground of L.A., reunites with sister Mia (Jordana Brewster), and sets out to infiltrate a gang of speed-racing drug traffickers whose leader is responsible for the death. Meanwhile, newly reinstated FBI Agent Brian O'Conner enters back into the fray of drag racing, going undercover as he seeks to bring in the same target. Dom's intended methods of apprehension are of a, shall we say, decidedly more bloodthirsty kind.

Directed by Justin Lin (2006's "The Fast and the Furious: Tokyo Drift"), "Fast & Furious" jump-starts into high gear with a pre-title setpiece set on a perilous mountain road that is so well shot, so cohesively edited, and so masterfully conceived for maximum taut impact that it prematurely gets the viewer's hopes up. Ironically, once the plot is set into motion the movie slowly but surely sputters out. The screenplay by Chris Morgan (2008's "Wanted") is as brashly dumb as all the earlier pictures in the series, but this time there is also a more rampant mean-spirited streak running through it. As Dom sets out for vengeance and Brian defies his superiors and sides once again with a man who is a criminal any way you look at it, both characters are stripped of detectable arcs. To complete their mission, they put innocent people's lives in danger without a moment's recognition, and yet the audience is meant to root for them. Why? At their ages, shouldn't they be thinking about turning a different leaf and doing something constructive with their futures?

While no scene is as good as the movie's first, there are a couple more interludes of adrenalized thrills, including a breathless drag race on the busy streets of Los Angeles. By comparison, the third-act centerpiece—a chase set in underground caves bridging the United States with Mexico—is anticlimactic and kind of dull. Better is what is suggested by the sly, if, again, unlawful ending. On its way to that point, the film does what is expected. The hot cars are objectified, though not as much as the gyrating women on display, each one portrayed as either a ho or a lesbian. As the camera oozes up their bodies, ogling their tight thighs and big breasts in PG-13 fashion, the film serves as little more than a preteen boy's wet dream.

As a result, the main cast members very nearly become window dressing, with Vin Diesel (2005's "The Pacifier") naturally outshining the typically uneven Paul Walker (2006's "Running Scared") even when having to utter the script's clunky dialogue. Female counterparts Jordana Brewster (2006's "The Texas Chainsaw Massacre: The Beginning") and Michelle Rodriguez (2006's "BloodRayne") have far less to do, the former saddled with a romantic subplot that goes nowhere and the latter displaying surprising depth and sensuality before all but disappearing by the 15-minute mark.

Less reliable than "The Fast and the Furious" but a little better than the silly "2 Fast 2 Furious" and "The Fast and the Furious: Tokyo Drift," "Fast & Furious" nonetheless is just more of the same. Director Justin Lin knows how to mount impressive stunts and action, but he is at a loss when it comes to dealing with characters and story. That he uses up his most inventive and large-scale sequence right from the get-go spells trouble for the 95 minutes that follow. Before too long, "Fast & Furious" is more interminable than its title promises.