After three hit movies, a failed spinoff, and nearly a decade since he reprised the role of reluctant assassin, Matt Damon returns with "Jason Bourne." But considering the half-hearted mess delivered in place of a stirring sequel, you'll wish he hadn't.

"Jason Bourne" picks up with its titular spy adrift in underground boxing matches, where he swiftly defeats his burly opponents, then dashes off into the shadows. But Bourne is pulled back into the CIA's spotlight when Nicky Parson (Julia Stiles) is caught hacking their black operation files. CIA director Robert Dewey (Tommy Lee Jones) is determined to bring him down for good with the help of a nameless assassin (Vincent Cassel). But an up-and-coming agent (Alicia Vikander) hopes to help Bourne reconnect to his past, and re-enlist in the CIA. There's also a subplot about a Mark Zuckerberg-like tech genius (Riz Ahmed), who doesn't want to allow the agency access to his system, because he values the privacy of his users. But this thread has absolutely nothing to do with Bourne's, and its insertion feels like haphazard filler at best.

While the first three "Bourne" films offered tight narratives of intrigue and personal stakes, "Jason Bourne" feels every step their pale imitation. Notably, Tony Gilroy, who had a hand in writing "The Bourne Identity," "The Bourne Supremacy," "The Bourne Ultimatum" and the Jeremy Renner-fronted "The Bourne Legacy," has nothing to do with this sloppy screenplay that checks off far-flung locations, but never bothers to give its characters dimension.

The return of "Supremacy" and "Ultimatum" director Paul Greengrass was supposed to herald a return to form for the franchise. And though Greengrass pulled together an extraordinary cast of movie stars and Oscar winners, he offers them one-dimensional characters, atrociously lame dialogue, and claustrophobic cinematography in place of genuine drama. Characters speak in naked agendas with lip-service to privacy, freedom, loyalty and patriotism. Rather than allowing actors to embody motivations, "Jason Bourne" uses the crude and hackneyed approach of having characters read about each other in files and online articles, complete with zooms and bolded quotes to be sure the audience gets Bourne's exact state of mind. You know, instead of allowing Damon to perform that.

Vincent Cassel, the French star who exuded glorious menace as a ballet director in "Black Swan," is given nothing to do but stride about and glower between blowing away randos without blinking an eye. Alicia Vikander, who won an Academy Award for "The Danish Girl" and will front the "Tomb Raider" reboot, is robbed a chance to play anything but steely reserve or do anything in the way of action. Suffocated in scenes full of shifty stares and desert-dry dialogue, her talents are completely wasted, as is our time.

Julia Stiles gets some plaintive looks and a big hero moment, but her time on screen is cruelly brief. The classically cantankerous Tommy Lee Jones clearly showed up for the paycheck, not the project. He not only seems like he doesn't want to be in this movie, but also looks like he doesn't want to live on this planet anymore. His apathy is so profound that it earned derisive laughs from the audience.

But what about Bourne? You might well be bellowing, hanging on to a slim strand of hope that Matt Damon's star power will save this stinker from being chucked onto the dumpster fire of this summer's regrettable sequels. Sorry. Even though the movie is directly named for his character, there is shockingly little screen time for Damon. Between bouncing back and forth between warring CIA factions, and checking in on the social media privacy subplot, the movie gives us little of its central star, and what little screen time beleaguered Bourne does have is often little more than him fixing his sad stare into the mid-distance.

When we finally do get to some big Bourne action scenes, Greengrass' confounding close-ups and handheld-camera fetish makes them incoherent. You won't believe how much of this movie is literally out of focus. Action sequences go by in blurs of color, blares of sound, and clouds of confusion. Greengrass' staging wastes incredible backdrops, most egregiously the much-anticipated car chase down the Las Vegas strip. Whipping past wildly lit casinos, most of the shots are close-ups of the cars! So the vibrant production values inherent in the location are infuriatingly out of frame. The spectacle is shot. But worse still, the combination of shaky handheld and choking close-ups means that the action itself is frequently hard to read. In the final showdown between Damon and Cassel, the violence is offscreen, undercutting what should be a defining moment in the film.

It's positively astounding how boring "Jason Bourne" is.

Despite a celebrated director and a remarkable cast, this summer dud delivers eyeroll-inducing dialogue, incomprehensible action sequences, performances that make each actor look either bored or bad, and visual storytelling so blatant that it insinuates the audience are idiots. As an ardent fan of the first film, I marvel at how far this franchise has fallen.

Now if you'll excuse me, I need scrub this slop from my head canon.

"Jason Bourne" opens Friday.