John Travolta continues his slippery slide back down to the hell whence he sprang with “Swordfish,” a very loud yet curiously half-hearted attempt at cyber suspense.

Travolta plays Gabriel Shear, a man who has become wealthy through high-tech bank-robbing, thanks to help from some of the world’s best computer hackers. He has plans to lift a ton of left-over federal money and sends his girlfriend, Ginger (Halle Berry), so named so they can make a “Gilligan’s Island” joke, to recruit Stanley Jobson (Hugh Jackman).

Stanley used to be the best hacker in the business, but is now barred from touching so much as an ATM as a condition of his parole. Ginger convinces Stanley to help by promising to get him custody of his little girl, Holly (Camryn Grimes), who is currently cared for by her porn-star mother and porn-director father. (This is a better home for her than her reformed white-collar-criminal father?)

Stanley comes to realize the depths of Gabriel’s insanity and the foolishness of the plot, but cannot get out because of his devotion to Holly. Ginger, meanwhile, tells him she’s a government agent trying to get at Gabriel.

If Travolta, all hammy and unbelievable as he tries to regain his “Face/Off” glory, takes class away from the proceedings, Don Cheadle (“Traffic”) adds it as an FBI agent pursuing both Stanley and Gabriel. Cheadle needs more starring roles, and Travolta — now a parody of his former screen presence — needs fewer.

Directed by Dominic Sena (“Gone in 60 Seconds”), “Swordfish” uses ultra-modern trappings but fills them with time-worn cliches. Bullet-heavy car chase in which only the right people are killed? Check. Brilliant villain who expresses high-minded political philosophy as the reason for his deeds? Yep. Hero’s daughter held hostage while clutching a teddy bear? Oh, yeah.

There’s also a fair amount of stuff done just because it would look cool, like suspending a bus from a helicopter and including a 360-degree slow-motion pan shot in the middle of an explosion — both of which are more impressive than necessary.

Skip Woods’ mechanical script has characters who speak in oblique action-flick ambiguities, attempting ominousness but achieving absurdity. It also makes a fatal misstep: The film’s prologue cements Gabriel’s evilness, making the rest of the movie — which takes place four days earlier and leads up to the prologue — less exciting, as there’s no chance for a reversal, twist or switcheroo. No chance it will turn out the FBI agent is the bad guy, for example, and Gabriel is the hero, because we’ve already seen Gabriel make a woman explode in the middle of the street.

Which in fact is what the movie does. It explodes in the middle of the street. While mindless blow-up films are diverting, one wonders why audiences would pay money to see this one when they could just stay home and rent “Die Hard” or “Terminator 2” and see essentially the same tricks done better and with more wit.

C- (; R, frequent harsh profanity, explosions and violence, a lot of nudity, strong sexuality.)