When you look at the cast list for The Accountant, which includes two Oscar winners (star Ben Affleck and J.K. Simmons) and two Oscar nominees (John Lithgow and Anna Kendrick), it sets up expectations that director Gavin O’Connor’s ridiculous yet flat crime drama never once meets during its bloated 128-minute running time.

Affleck plays Christian Wolff, the titular accountant. Perhaps it’s his Asperger’s syndrome that makes him so great with numbers. But it’s his upbringing as a Army brat (played in flashbacks to his youth by Seth Lee) under the militaristic rule of his borderline abusive father (Robert C. Treveiler) that has made him just as good with a gun. After all, watching a plastic action hero like Affleck simply tapping on a calculator for more than two hours would be pretty boring, right? Screenwriter Bill Dubuque seems to think so; he may as well have titled his script The Assassin, since the ratio of number-crunching to bone-crunching would look pretty stark on a spreadsheet.

But then, O’Connor’s film might get confused with Hsiao-Hsien Hou’s lyrical masterpiece from last year, also named The Assassin. Well, to anyone lacking a brain, that is. But for those poor thinking souls unfortunate enough to end up in a theater showing The Accountant, be aware that you might be more entertained spending time with your accountant.

Inexplicably, Dubuque’s script was very highly regarded in Hollywood, having earned a spot on 2011’s Black List, a compilation of top-rated unproduced screenplays. And something must have attracted Affleck, Simmons, Lithgow and Kendrick to this project, after all. Still, this only serves to support the theory that no one reads anymore—and that includes recent Emmy winner Jeffrey Tambor (Transparent) and rising star Jon Bernthal (The Walking Dead), who appears here as a second assassin, but presumably one without a sideline as an accountant. Alas, a world filled with bookkeeping killers might actually be interesting.

Instead, Dubuque has cooked up a sloppily conceived parallel plot focusing on Marybeth Medina (Cynthia Addai-Robinson), a poorly vetted Treasury Department analyst with a secret past—a past that her boss, Crime Enforcement Division director Raymond King (Simmons), is threatening to expose if she doesn’t do his bidding and track down the “black money” operator who’s been cooking the books of some of the world’s worst men. Naturally, she’ll come to discover that this man is none other than Christian Wolff. And if you think Christian’s lupine surname seems a bit overwritten, know that it’s just one of a number of aliases he uses in this equally overwritten film, which finds Wolff un-cooking the books at an advanced robotics company run by genius Lamar Black (Lithgow) after junior accounting clerk Dana Cummings (Kendrick) discovers a multimillion-dollar discrepancy.

You’ll guess who’s behind the embezzling scheme, though neither Wolff nor Cummings can—perhaps because they’re blinded from making goo-goo eyes at one another. Their tunnel vision continues when Wolff saves Cummings’ life after she’s been targeted for Knowing Too Much, quickly dispatching some hitmen who’ve been hired to terminate her. He may be socially awkward, but she sure finds him sexy when he’s smashing her would-be killers’ skulls against her bathroom walls. Ah, modern romance.

As the two go on the run, they’re pursued by Bernthal’s shadowy assassin, Medina and King, who has a secret history of his own. But not to worry—we’ll soon find out what it is during one of the comically frequent flashbacks that fill in the desperately uninteresting backstory.

O’Connor, a journeyman who’s never quite matched the success of his first hit, Olympic hockey drama Miracle, treats these events with a deadly seriousness that ironically undercuts any sense of drama that might invest you in such an absurd potboiler. It’s interesting to wonder what Affleck—who’s built a nice second career as a director—might have done with this same script, having navigated his way around a pair of Boston-based thrillers (2007’s Gone Baby Gone and 2010’s The Town), along with a surprise Best Picture winner (2012’s Argo). Say what you will about his acting, but the former Cantabrigian knows how to pace a film and set a tone, two elements that are woefully mismanaged here. Instead, we’re left with a mess of a movie that could have used a little levity. It’s this lack of self-awareness that’s the real killer here.

The Accountant   *1/2

Starring Ben Affleck, Anna Kendrick, Jon Bernthal, J.K. Simmons, John Lithgow, Cynthia Addai-Robinson, Robert C. Treveiler, Mary Kraft, Alison Wright, Seth Lee, Jake Presley, Izzy Fenech and Jeffrey Tambor. Directed by Gavin O’Connor. Written by Bill Dubuque. At Assembly Row, Boston Common, Fenway and in the suburbs.