The updating of the old TV show that Antoine Fuqua and Denzel Washington made a few years ago was obviously designed to provide a potential franchise for the actor—who until now has never even attempted a sequel to any of his films—and so “The Equalizer 2” comes as no surprise. It is, however, a terrible disappointment, superior to its predecessor only visually, thanks to the slick cinematography of Oliver Wood, far preferable to Mauro Fiore’s in the first movie.

In this second installment, Washington’s Robert McCall has embraced his role as a guardian angel for people in difficult situations, though unlike Edward Woodward in the television program, he doesn’t advertise for clients, instead aiding those he comes upon in his ordinary life (he’s now a Lyft driver, having apparently given up his job at the big home depot-style store from the first film). In a prologue, we see him retrieving the daughter of a woman later shown to be the owner of his favorite bookstore; the girl has been abducted by her father, a slimy Turkish fellow (Adam Karst), and McCall disguises himself as an Islamic scholar to accost the man on a train in Turkey, effortlessly dealing with the guy’s brutish companions in the process. (His latest purchase from the store, incidentally, is the last of the hundred books he’s reading in memory of his late wife Vivienne—Marcel Proust’s “Remembrance of Things Past.” If he’s anything like the rest of us, that should keep him busy for years to come.)

The major problem with “Equalizer 2,” though, is that Washington’s McCall doesn’t resemble a real human being at all. In a coda Miles (Ashton Sanders), the neighborhood teen he’s taken under his wing to keep him from becoming a gangsta, is writing a comic book based on him, and describes his savior as a superhero. It’s not an inappropriate term. McCall is always one, two or three steps ahead of every opponent. He can intuit what happened in any past situation simply by thinking intently about it (in one sequence he “transports” himself into a room where a couple has been murdered to understand how it happened.) When it comes to actual fighting, he can take care of four or five opponents without breaking a sweat (as he does when dealing out righteous punishment to a bunch of arrogant yuppies who’ve dumped a girl they’ve abused into his car). It’s hard to work up any concern for his wellbeing because—apart from his widower’s grief—McCall appears invincible.

This makes it rather easy of Washington to play him. Perhaps “play” isn’t quite the right word, because unflappability comes so easily for the actor that he seems simply to glide through the movie without much effort, except for the occasional bout of running around or hand-to-hand combat. He certainly isn’t stretched dramatically by the role.

Nor, in fact, is McCall much stressed by the plot contrived for him by Richard Wenk, the initial complications or which are explained away by the simplest (and most implausible) of explanations. It all begins with the killing of that couple in Brussels by a trio of thugs, one of whom is revealed as Resnik (Jonathan Scarfe). Since the man killed was involved with the American spy services, McCall’s old boss and friend Susan Plummer (Melissa Leo), one of the few who know he’s still alive, is sent to Belgium with her aide—and McCall’s old comrade-in-arms, Dave York (Pedro Pascal), who isn’t aware of it–to look into the presumed murder-suicide. While there, Susan is brutally killed by a couple of thugs in her hotel room—supposedly in a botched robbery. But McCall doesn’t believe that, and so he undertakes to find out the truth.

It wouldn’t be right to reveal the identity of the ultimate villains, even if it’s not hard to figure who they are. Suffice to say that the whole business winds up in one of the most ridiculous confrontations ever, set in the middle of a hurricane that’s hitting the coastal Massachusetts town where Robert and Vivienne used to live, running a bakery no less. Why a hurricane? Presumably just because Wenk and Fuqua thought it would be a cool way of differentiating the face-off from similar scenes in other movies. The locale does raise some logical problems, though: the town has supposedly been evacuated, yet the electricity is still up and running, since one of our hero’s elaborate stratagems involved a couple of fans. Thankfully McCall doesn’t use a nail gun this time, but he does employ a harpoon that just happens to be lying around against one foe.

It’s a foregone conclusion, of course, that McCall will take care of business and avenge Susan’s death (in the process taking time to save her husband Brian from the killers—he’s played by Bill Pullman, who has nothing to do but look alternately befuddled and grief-stricken). But the rationale behind all the mayhem is just blithely described as a matter of “tying up loose ends,” which is a signal of truly lazy writing. (There’s another sequence, in which McCall is attacked by a knife-wielding would-be assassin in his car, that, one guesses, is to be explained by the same trite formulation—it seems totally extraneous, and is also marked by some very clumsy action choreography and editing.) By comparison the old TV show was a model of cleverness and clarity.

As if all that weren’t enough for McCall to handle, he has time to solve other problems. There’s the whole Miles subplot, for example, in which the poor kid gets dragged into our hero’s business and has to be rescued from extreme peril. (Let’s just say he becomes another “loose end.” The villains never seem to sew matters up effectively.) But even that thread pales beside the one about Sam Rubinstein (Orson Bean, with a visage so weathered that he looks at least a hundred years old), an elderly Holocaust survivor who’s a regular customer of McCall’s. He’s trying to recover a painting of his sister from whom he was separated in the war, and apparently in the moments he can spare from his more pressing obligations McCall manages, through means the movie doesn’t even bother to explain, to contrive an ending to the man’s search so sentimentally waterlogged that it rivals the close of “Going My Way.”

It probably doesn’t matter that “The Equalizer 2” is such a preposterous and pedestrian action-thriller; it will likely make a mint. And that’s okay, so long as Washington uses the cachet it gives him to undertake projects like his brilliant adaptation of August Wilson’s “Fences.” For another film of that quality, it would be worth sitting through even a third “Equalizer.”