It seemed like an odd combination for a movie hero — a guy with autism who uses his abilities as a math savant to cook the books for criminals and has the fighting and killing skills of a special forces soldier.

In the 2016 movie, “The Accountant,” that combo worked because Ben Affleck played the character, Christian Woolf, as aloof and socially inept but brilliant and determined. The movie had a very clever script by Bill Dubuque and a really solid supporting cast, including Anna Kendrick, Jon Bernthal, John Lithgow, Jeffrey Tambor, JK Simmons, and Cynthia Addai-Robinson. Some of its best sequences involved Woolf trying to figure out how large sums of money had been moved around illegally by a robotics company’s executives. And like students in an elementary school math class, he had to show his work.

Nine years later, we get the sequel, “The Accountant 2,” which is missing some important parts of the puzzle (Kendrick, Lithgow, and Tambor) as well as any evidence that Woolf is a high-functioning math genius. Instead, what we get is a very by-the-books action movie which starts out with a scene in which Simmons dies (that’s only a tiny spoiler, believe me), so his former colleague Addai-Robinson tracks down Woolf and convinces him to root out the killer or killers.

From there, Dubuque’s script loads up Woolf with other obstacles to overcome and mysteries to solve with the help of Bernthal, who returns as his brother. There are Central American refugees, a female assassin who must have studied Charlize Theron in “Atomic Blonde,” and a missing boy being held along with other kids in Juárez, Mexico. While Affleck is effective keeping his character in check and never overacting, director Gavin O’Connor (who also helmed the original) must have told Bernthal to chew every piece of scenery he could while never using his inside voice.

In an attempt to balance the serious John Wick vibes, Dubuque and O’Connor inserted a couple of set pieces that are supposed to be light and amusing. In one, Woolf sits through several awkward attempts at a speed-dating event. In the other, he’s attracted to a woman at a country bar so much he joins her in a line dance. Hey, look, it’s the neurodivergent killing machine doing a Texas Two-Step!

Aside from those out-of-nowhere scenes, “The Accountant 2” keeps coming down to whether Affleck and Bernthal can take out a lot of bad guys in repeated battles involving a ridiculous amount of weapons and some lethal hand-to-hand combat, too. I never had any doubt how those fights would end, and you won’t either. I’d love to see the auditions reel in which the extras only had to show how well they can fall down after being shot in the head or the chest, since that’s pretty much all they get to do.

This sequel isn’t as bad as the one I reviewed last week (“Another Simple Favor”), but it doesn’t live up to the wit and humanity of the original. I’m giving “The Accountant 2” a 5 out of 10. You don’t need Christian Woolf to tell you that’s not a good enough number.

In theaters now.