I first noticed Vin Diesel as the tormented sidekick hustler in the small 2000 film "Boiler Room," where he showed that all-too-rare quality of true movie stars by making everyone else on screen invisible next to him. Then, in both "The Fast and the Furious" (2001) and "XXX" (2002), he surmounted bad writing and inept direction to solidify his position as Hollywood's best new action hero.

Now, though, as a maverick D.E.A. agent in Los Angeles, he's confronted with a story that's baffling in its incoherence, and direction by F. Gary Gray that has thrown out everything but shootouts, Gray's motto obviously being the more of them the better. Diesel is Sean Vetter, who as the film begins leads a Mexican-U.S. raid on drug lord Meme Lucero (Geno Silva). Since the film doesn't bother with niceties like extradition and trial, Meme is now serving consecutive life sentences at a California prison. But the mysterious Diablo has taken over Meme's operation, and by way of revenge his gang kills Sean's lovely wife Stacy (Jacqueline Obradors) right in their Malibu oceanfront home - and is anybody concerned that this government-pay-scale D.E.A. agent actually OWNS a Malibu cottage?

Now Sean goes crazy (let's just say he overreacts when a drug suspect taunts him about his wife, and thereby turns an arrest into a bloodbath in which three agents die), has his badge taken away, goes to the imprisoned Meme for help in locating Diablo, and decides to go back into Mexico to take him out. Picking up his loyal D.E.A. sidekick Demetrius (Larenz Tate), who can't ever say no to Sean, the new little team shows up at Drug Central and does its thing, only to find that the now-escaped Meme was behind it all the time.

There's more, including Sean's repeated visits to his wife's grave - a stone that seems to have been set up in someone's front yard along with about twenty others, for the purpose of showing Vetter on his knees before the inscription 'Lost but always remembered.' Wow. The writers, Christian Gudegast and Paul Scheuring, have shoehorned so much repetitious action into the film's 112 minutes that they've left out any coherent story. The best action films make us participants in them; we ride alongside the hero, we empathize, we suffer as well. Here, with the exception of the sunset-over-the-Pacific-from-the-deck-of-the-Malibu-house shots as Sean and Stacy cuddle, there's nothing but mindless shooting, which by definition is a bore to watch.