If you want to enjoy Liam Neeson’s latest high-speed thriller at all, you’ll have to do more than merely suspend disbelief. You’ll have to grab it, smash it into little pieces and toss them into a black hole. The various “Taken” movies, “Unknown” and “Non-Stop” were all highly implausible, but “The Commuter” goes far further, moving from ridiculous to absurd to ludicrous and then wherever lies beyond that. It lurches off the rails much sooner than the train on which most of the action is set. But it’s well-made from a purely technical perspective.

This time around Neeson is Michael MacCauley, an insurance salesman who—as a means of explaining the extraordinary skills he’ll need to exhibit in the course of the movie—used to be a supremely capable police detective. Just fired from his job, he faces economic disaster—two mortgages on his suburban house and looming bills for his son’s college costs. After getting a bit of sympathy from his old partner Murphy (Patrick Wilson) at the local cops’ watering hole, he boards his usual train home.

Settling in, he’s accosted by a strange woman calling herself simply Joanna (Vera Farmiga) who offers him a hundred grand to identify a passenger on the train named Prim, and tag a bag that person is carrying with a GPS device before the target gets off. When the cash isn’t enough of an inducement, threats to his wife (Elizabeth McGovern) and son (Dean-Charles Chapman) are added to the mix. As her occasional phone calls indicate, Joanna is keeping close tabs on everything Michael does, and when he tries to induce a fellow passenger (Jonathan Banks) to get in touch with the police for him, she arranges for the poor guy to suffer an unfortunate accident.

So Michael is compelled to sniff out Prim—a difficult task, since the only thing he knows about him/her is the person’s intended point of disembarkation. It doesn’t help that the train is suffering from a conked-out air conditioning system during a sweltering day, and that it’s filled by the screenwriters with so many passengers serving as red herrings that it might as well be a speeding fish market; “Murder on the Orient Express” runs a distant second place in that department.

Ferreting through the possibilities gets the sweating, increasingly frazzled MacCauley into some serious scrapes; indeed, he’s involved in two or three knock-down, drag-’em-out brawls that leave him bloody and battered, at least until the next scene. At one point, as tradition dictates in such railway yarns, he’s even half-hanging out of a window as a train is seen approaching from the opposite direction on an adjacent track. You know what happens then. Luckily no one is ever around to see these fights, so that even though some local cops are called in to look over the train at one point, Michael can continue his search unimpeded by the authorities.

And what would a movie of this kind have to offer if, toward the close, it didn’t provide a massive crash? Of course you have to arrange things so that neither your hero nor the people you’ve come if not to like, at least to recognize as unworthy of death, will not be seriously injured in the mayhem. And Joanna has to get her comeuppance—though how that’s brought about remains an even greater mystery than the identity of the ultimate villain—because if you’ve ever seen a movie before, you’ll recognize the person even before the train leaves the station.

That’s only the first of the flaws in the script, which is filled with a huge number of plot holes, beginning with the fact that the entire nefarious plot is so stupidly intricate. Since the plotters know the station where their target will be getting off, why not just lie in wait for him/her there? (Certainly the FBI men shown waiting there could be easily disposed of—and why didn’t they arrange to take the person into protective custody earlier?) And since in the end the schemers show themselves willing to kill everyone on the train, why not just do that to start with? The whole scenario is so far-fetched that it will be virtually impossible for anyone unwilling to put his brain completely on hold to stick along for the ride.

As usual, Collet-Serra attempts to cover up the massive implausibility with a barrage of speed, noise and action, and with the help of cinematographer Paul Cameron, composer Roque Baños and the effects team, he does a fairly good job of it—many viewers will probably be willing to swallow what’s going on simply because it’s pushing ahead so fast. That also testimony to the sharp editing of Nicolas de Toth, though—to be honest—his best work actually occurs at the very beginning, in a time-jumping montage that tries to provide Michael with some depth of character by offering brief scenes of his home life.

The tactic doesn’t actually work, because the guy remains pretty much a cardboard figure. But that doesn’t matter when he’s played by Neeson. By now the core audience with a taste for this sort of mindless macho farrago knows what he’ll deliver, and he will fulfill their expectations here. But underneath the nonsense he shows glimmers of what a fine actor he is, and what he might have brought to a narrative along these lines had it been constructed like a Hitchcockian “wrong man” tale rather than another “Taken” ripoff. It’s a pity he’s become trapped in such stuff, though it’s doubtlessly proven very beneficial to his bank account. Everybody else in the cast goes through their assigned paces adequately, with Farmiga and Banks most notable among the large ensemble.

“The Commuter” is a stop you should pass by on the way to a better destination in another auditorium.