Lisbeth Salander, the tortured, brooding heroine of Stieg Larsson’s Millennium trilogy, and of the four films based on them (three Swedish made-for-TV features starring Noomi Rapace and David Fincher’s remake of “The Girl With the Dragon Tattoo” with Rooney Mara) returns—after a fashion—in “The Girl in the Spider’s Web.”

“After a fashion” is an appropriate qualification, because the script for Fede Alvarez’s film—by Alvarez, Jay Basu and Steven Knight—is based on the novel by David Lagercrantz that continued the series after Larsson’s untimely death, and in rebooting the franchise, the movie makes major changes in the character’s backstory and her modus operandi. Oh, Lisbeth remains a sort of feminist vigilante—a prologue shows her wreaking vengeance on a wealthy crumb who beats up his wife as well as hookers of his choosing—and a lesbian (though the latter is toned down considerably, being relegated to a couple of short, tame scenes); and she still has that tattoo. But she’s been transformed into a sort of typical superheroine with extraordinary abilities (wondrous computer hacking skills, endless resources of energy, and a determination to plow on despite physical injury), though not, in the event, an especially capable one—she’s constantly being outmaneuvered, beaten up and put in extreme jeopardy. Suffering seems to be her default condition.

And the plot she’s thrust into isn’t the sort of personal mystery she addressed in the past, but one of those silly potential end-of-the-world scenarios with lots of international ramifications—though Spectre might not be involved, another evil global group is, and Lisbeth acts rather like a pint-sized Jane Bond.

It all starts when, after taking care of that nasty wife-beater, she’s contacted by Franz Balder (Stephen Merchant), an erstwhile software genius at America’s NSA who left Washington after developing a program called FireFall, which can pinpoint the position of all the nuclear missiles on the globe and provide their firing codes. That’s the MacGuffin of the convoluted plot, although there’s another in the form of the place where Balder has hidden the passwords that will activate the program.

Franz wants Lisbeth to hack into the NSA computers and steal FireFall to ensure that such a dangerous system is not in the hands of any government. She does so, but the theft catches the eye of NSA cyber specialist Ed Needham (Lakeith Stanfield), who tracks the source to Sweden and arrives in Stockholm to find the perpetrator and retrieve the program. He’s immediately detained by Gabriela Grane (Synnøve Macody Lund), second in command at SAPO (the Swedish intelligence service), who says it’s her business, not his.

But that’s the least of Lisbeth’s problems. While SAPO has put Franz and his autistic young son August (Christopher Convery) in a supposed safe house, she is attacked in her warehouse lair by a bunch of thugs, who try to blow her up; they swipe Lisbeth’s laptop with FireFall on it, kill Franz and take August hostage. Lisbeth recovers from her injuries quickly enough to free the boy from their clutches after a car chase, but in the process discovers that the leader of the gang, called the Spiders, is none other than her sister Camilla (Sylvia Hoeks), who—as we’ve been shown in a prologue—Lisbeth was forced to leave with their malevolent, abusive father when they were children (played in flashback by Beau Gadsdon and Carlotta von Falkenhayn). Camilla, whom Lisbeth thought dead, has taken over daddy’s unsavory business.

Complications escalate as Lisbeth tries to recover the computer and face her sister. Also involved in her efforts are Needham, a computer whiz called Plague (Cameron Britton) who serves to keep track of everything and help her out as needed, and investigative reporter Mikael Blomkvist (Sverrir Gudnason). All of them save her bacon over and over again as she does battle against Camilla, who bears what seems a rather unreasonable grudge against her sister for “abandoning” her. You might find yourself wondering just how super a heroine Lisbeth is—especially since at a couple of points she could decisively end the problem by pumping a bullet into her opponent but wilts and doesn’t do so—but then, if she were ruthless perhaps the makers think we wouldn’t care about her.

And she does have that superhacker Plague, who can apparently do almost anything with his equipment; she wins over Needham pretty easily, despite his supposed cynicism; and she has the loyalty of friends, especially Blomkvist (though to be frank, he’s an awfully pallid character this time around, and the bland Gudnason does nothing to make him more interesting). She also seems to have a way with kids, at least autistic ones like August, whom Convery plays with solemn reticence.

Of course, Lisbeth’s relationship with Camilla is fraught, and actually not terribly engaging, since both are such traumatized individuals, though they respond to their childhood tragedy in divergent ways. Lisbeth, of course, is a quivering mass of nerves, who has compensated by forcing herself to become physically strong and self-reliant. Camilla, meanwhile, is an icy, brittle snow queen, emotionless until she cracks at the end. They also look very different: Lisbeth dresses in her usual black duds and has close-cropped black hair, while Camilla is a study in scarlet, with a long, bright red coat to complement her abundant blonde hair.

That red garb is set against the dank, blue-gray images crafted by cinematographer Pedro Luque Briozzo, which make the Scandinavian locations themselves feel chilly and vaguely threatening; the effect isn’t quite as striking as the girl in red from “Schindler’s List,” but it comes close.

Hoeks, frankly, doesn’t make much of Camilla, but Foy proves a capable replacement for Mara, handling the role’s physical demands as well as the emotional ones. That’s important, because much of the movie is action-filled: there are chases with cars and motorcycles, as well as on foot; shoot-outs and knock-down fistfights, complete with martial-arts moves; explosions; and scenes of torture and its aftermath that might make the squeamish a mite queasy. While they’re all well handled by Alvarez and his stunt team, they’re not always ideally clear. The same is certainly true of the plot convolutions, which zoom ahead pretty quickly, with detailed explanation of the whys and wherefores often falling by the wayside. Some of the twists, especially toward the close, are pretty ridiculous; you might find yourself grinning at them, and not in pleasure.

As brainless action fodder, this extension of the Salander saga might pass muster with undemanding viewers, but it doesn’t really do justice to Larsson’s original dark vision of the eternal war between men and women. By reducing the girl with a dragon tattoo to a more conventional action heroine, the film makes her less interesting and itself more disposable.