Ben Affleck, Anna Kendrick, Jon Bernthal, Cynthia Addai-Robinson, J.K. Simmons, John Lithgow, Jeffrey Tambor

Gavin O’Connor

What if Jason Bourne wasn’t an amnesiac super-soldier but rather a high-functioning autistic man with comparable fighting skills? That appears to be the general idea behind Gavin O’Connor’s “The Accountant,” a film suffering from such an identity crisis that it’s unclear exactly what kind of movie he’s trying to make. Though it starts out as both a fairly generic crime procedural and a zen-like character study about an on-the-spectrum math genius struggling to lead a normal life, it completely changes gears midway through and transforms into a straight-up action thriller. The problem is that “The Accountant” never stops being those other movies either, resulting in a convoluted and tonally unbalanced mess that is occasionally entertaining but feels like it’s a few drafts away from a finished product.

Small-town accountant Christian Wolff (Ben Affleck) isn’t like everybody else. He’s highly intelligent, a proficient marksman and capable of winning a knife fight with only a belt. In fact, Christian isn’t even his real name; it’s just one of many aliases he uses to stay off the grid. Raised by his sadistic military father, who eschewed traditional therapy for an unorthodox childhood designed to prepare him for the toughness of the real world, the antisocial Christian now moonlights as a forensic accountant for dangerous criminal organizations, uncooking the books to locate missing money. Determined to stay one step ahead of the U.S. Treasury Department’s Financial Crimes division, led by director Raymond King (J.K. Simmons), Christian accepts a seemingly innocuous job auditing a high-profile robotics company after an accounting clerk named Dana (Anna Kendrick) discovers a discrepancy in the finances. But as Christian and Dana get closer to exposing the truth, they’re targeted by a contract killer (Jon Bernthal) who’s been hired by someone within the company to contain the leak.

For as problematic as its screenplay may be, “The Accountant” is an incredibly well-cast film. Although the autism angle makes Christian a difficult protagonist to identify with, Affleck delivers a solid performance that is much harder to pull off than it looks; it’s stoic and slightly wooden but not without charm. The rest of the cast also provides adequate support, even if they’re not really given enough to do in their respective roles. John Lithgow and Jeffrey Tambor only have a few scenes each, while the bubbly Kendrick is merely a plot device used to progress the story and lighten the mood. Bernthal and Simmons fare the best of the bunch, though the latter’s biggest contribution is a third-act information dump that grinds the movie to a halt. The whole government subplot, which also includes Cynthia Addai-Robinson as a talented Treasury analyst assigned to track down Christian, is mainly there to provide exposition for the audience, and yet without it, the film would still largely make sense.

Bill Dubuque’s script tries to cram way too much into the movie, and that ambition is ultimately its downfall, tripping over itself as it juggles the accumulating subplots. It also gets a little too cute with all the character reveals and twists, particularly one involving Bernthal’s smooth-talking enforcer that is telegraphed nearly an hour before it happens. Though “The Accountant” thrives when it embraces its B-movie roots, delivering some enjoyable “John Wick”-level action and dark comedy in the process, the film is so desperate not to be reduced to a silly genre flick (and boy does it get pretty silly at times) that it’s unwilling to let go of the stuff that’s dragging it down. This could have been the most original and emotionally engaging action movie since “The Bourne Identity,” but it doesn’t quite add up to the sum of its parts.