Friday’s sequel to “The Accountant” reunites Ben Affleck, 52, with Jon Berthnal, 48, and Cynthia Addai-Robinson, 40, from the 2016 original.

This time, Affleck’s autistic mathematical savant Christian Wolff must partner with his long estranged, hired assassin brother Brax (Bernthal) and U.S. Treasury Deputy Director Marybeth Medina (Addai-Robinson) to expose and survive a deadly conspiracy and its corps of assassins.

With a third “Accountant” already in the works, the question is: What took so long?

“Well, after the first one — it was successful and I was really proud of it,” Affleck, who also produced, said in a virtual press conference, “but it had a longer life in terms of the just real-life feedback that I get from people. What movies they would mention when they come up to me.

“So I definitely was aware, ‘Oh, wow! That movie seems to still being watched,’ which I think is also a function of the fact that streaming really started to take off after this movie.

“Also, I love this character. Gavin (O’Connor, the original’s director) and I both very much were drawn to the idea of bringing Jon back. We both felt there was a lot more to do.”

O’Connor and the original screenwriter Bill Dubuque, Affleck explained, “spent a lot of time in the intervening years developing and putting together in a quite typical of Gavin, meticulous, patient, detail-oriented, character-driven way, what it could be.

“Both were mindful of not wanting to repeat. Not wanting to just, ‘Hey, they like the first one. Let’s figure something out and do another one.’”

“There was certain DNA that was important to preserve in a sequel,” O’Connor, 61, offered. “After that, it was a lot of left turns trying to refill the tank in a very different way.

“I know we didn’t want to recycle the same thing that we did in the first film. So it was a matter of, How do we start recreating the character in a way that is putting him on a different journey, integrating Brax?

“And we wanted to bring Cynthia back. We knew the key in the ignition was to kill (someone) because I wanted it to be personal for both of these guys.

“Most importantly, we had these conversations about how I just wanted to make a movie that was fun and entertaining and put people in the seats where they would go to a movie theater, the lights would come down and have a communal experience.

“Where they can walk out of the theater and go, “Man, that was a (expletive) ball! That was a great time at the movies.’ That’s really what we were going for.”

“The Accountant 2” opens in theaters Friday