The naming of a movie, especially a new concept, can be tricky. It needs to be short enough that it rolls off people’s tongues easily, interesting enough that it conveys what the movie is about, and catchy enough that people will remember it when they head to the movie theater.

It’s difficult to argue that The Accountant accomplishes more than one of these goals, although the sheer blandness of the title may be enough for people to do a double take. That’s especially true when you understand that it stars Ben Affleck as Christian Wolff, an autistic man with a supernatural ability for math who cooks the books for criminals and, oh yeah, also happens to be a world-class action hero.

That’s a lot to digest for one character, but somehow the filmmakers make it all work. Also involved are Ray King (J.K. Simmons), a Treasury Department investigator whose white whale is Wolff; Marybeth Medina (Cynthia Addai-Robinson), a Treasury underling tasked with tracking Wolff down; Dana Cummings (Anna Kendrick), an accountant at a firm where Wolff takes a new contract job; and Brax (Jon Bernthal), an enforcer-for-hire who runs in the same orbit as Wolff.

Improbably, instead of being unnecessary distractions, the multiple subplots all add layers to the main story. Also of help are flashbacks to Wolff’s tumultuous childhood, scenes that underscore exactly why he becomes the type of person he is. Director Gavin O’Connor and writer Bill Dubuque do an effective job of juggling all of the disparate elements to make a film that’s smart, funny, and surprisingly tense.

That’s not to say that it’s perfect. There are several points where the situations would be laughable in a bad way if you’re not invested in the story, and the logic of the film’s third act falls apart the more you think about it. But the strength of the rest of the film allows you to overlook its flaws, especially when Affleck springs into action.

For an actor who was once as reviled as he was during his Daredevil/Gigli period, Affleck now seems to know exactly how to get to the center of a character. Wolff could come off as completely ridiculous, with his tics, monotone responses, and lack of emotion. But Affleck pulls it off the majority of the time, making Wolff into both a sympathetic and fearsome character, a duality you don’t often see.

The Accountant is a prime example of never judge a book by its cover. The banality of the title hides a crackerjack movie that, given its effectiveness and Hollywood tendencies, could very well turn into a new franchise for Affleck.