“The Accountant 2” is a blithely nonsensical, enjoyably vulgar follow-up to “The Accountant” (2016) about a numbers whiz played by Ben Affleck, who has impeccable marksmanship and shaky people skills. Like the first movie, the sequel embraces violence without apology, slathers the screen with (fake) blood and unleashes a small army of stunt performers who convincingly play dead. This one has another complicated intrigue and a great deal of plot, though most of the tension comes from watching Affleck struggle to suppress a smile while sharing the screen with an exuberantly showboating Jon Bernthal.

The sequel picks up eight years after the first movie introduced Affleck’s Christian Wolff, a brilliant autistic forensic accountant who moonlights as a freelance avenger with help from friends. (The movie’s breezy embrace of cliché includes the stereotype of the autistic savant.) J.K. Simmons shows up as Ray King, the former director of the Treasury Department’s criminal investigations unit. He briefly enters wearing a cap and soon exits without a pulse, though not before setting the story in motion. Cue the gunfire and choreographed chaos, as well as amnesia, plastic surgery, trafficked women, child hostages and a miscellany of villains, ones who are cruel enough to bring out (and amply stoke) the audience’s bloodlust.

King’s successor, Marybeth Medina (Cynthia Addai-Robinson), re-enters afterward to help nudge the story forward as does Christian’s younger brother, Braxton (Bernthal). Everything (and everyone) flows together more or less, even when the story strains credulity, as B-movie shoot-em-ups often do. It helps that there’s less back story here than in the first movie, which revisited Christian’s brutal childhood and his Oedipally nurtured violent skill set. That frees up the filmmakers — like the first movie, this was written by Bill Dubuque and directed by Gavin O’Connor — to focus on keeping all the people and parts nicely moving. Among these is Affleck, whose controlled, inward-directed performance holds the center.

One irresistible draw of a diversion like this is that while its good guys are often bad, its bad guys are assuredly worse. Both Christian and especially Braxton have obvious moral failings (ha!), but their kill counts are never the problem, which puts them in fine, crowded company. American movies love gunslingers, after all, whether they have Texas or British accents, wear white hats or gray ones like Christian. Among these are the seemingly ordinary men — blue-collar types, next-door dads, computer jockeys — who, when hard push comes to brutal shove comes to catastrophic violence, will take off their glasses à la Clark Kent to transform into near-mystically gifted avengers. They lock and load, restoring order to a broken world.