It's a typical day at the office until a Russian spy wanders in and reveals he knows the place is a CIA front. Boy, if I had a nickel for every time that happened, I'd probably have more money than the producers of Salt spent on the script for their movie. The punchline, of course, being that no one has ever mistaken what I do for a living for anything remotely intelligent, much less Central Intelligence.

But seriously, this is what happens at the start of Salt, an action film starring Angelina Jolie as the title character, Evelyn Salt. Agent Salt's world gets turned upside down when a Soviet bad guy (Daniel Olbrychski) walks into her building and gives himself up. He spins a yarn about a Russian scheme to plant sleeper agents throughout the United States, hiding in plain sight until such a day as they are required to strike. Lee Harvey Oswald was the first, the success story that allowed one Soviet spook to start a school devoted solely to raising children to be the most shadowy of covert agents. One such agent is going to kill the Russian president at an upcoming public event, setting off a war between old foes. That agent is Evelyn Salt.

Salt claims ignorance. She thinks this is an attempt to blow her cover and destroy her life. She fears for her husband (August Diehl), a scientist who loves bugs and who once saved her in North Korea. Her boss, Ted Winter (Liev Schreiber), trusts his operative, but counterintelligence agent Peabody (Chiwetel Ejiofor) isn't taking chances. He wants Salt contained. She has other ideas. But is she really busting loose in order to protect her husband, or is she everything the crazy old Russian said she is?

To the credit of director Phillip Noyce (Patriot Games, The Quiet American), he doesn't tip his hand. I spent the first hour of the movie--a mostly good hour, I might add--not being sure just where Salt was going. When Evelyn explains herself, it sounds credible, but then her actions give an entirely different impression. This part of the movie plays like a female answer to Jason Bourne, with Angelina Jolie putting her training to good use and kicking a whole lot of ass. We know what her training is, too, because Noyce conveniently shows us a smart phone screen that lays it all out, apparently so we will believe some of the crazy stunts she's going to get into. She leaps across moving vehicles on the freeway, scales walls, even finds an inventive use for a taser as a driving tool. It's pretty entertaining stuff, even if some of the logistics don't quite align. (At one point, she sets a bomb under a floor and it manages to cause the ceiling up above said floor to explode, as well.) It's not as aesthetically rigorous as any of the Bourne films, it's more like a slick approximation of the same, but I still went for it. Sue me, I like seeing amazingly beautiful women in exciting action sequences. You really have to wonder why James Bond got so many movies and Modesty Blaise has only had two.

Sadly, all the stuff that worked so well in those first 60 minutes goes right to hell in the final 40. Basically, Salt is taken into custody again, and naturally she escapes again, and then the movie starts to fall apart piece by piece. Every scene that follows her getaway is increasingly dumber than the last, until every ounce of interior logic is destroyed. At one point, after Salt pulls a double-cross and leaves a huge body count behind, I started to think that maybe the movie was getting so bonkers that it just might be some weird kind of awesome. But no, it really was just bonkers.

The screenplay for Salt was written by Kurt Wimmer, who most recently wrote the scripts for Street Kings and Law Abiding Citizen. Perhaps I lay too much blame at his feet, perhaps not. He's had third act trouble before, and his films do tend to rely on convenient screenwriting tricks, stuff like perfectly timed text messages or bad expository dialogue or worse, information repeatedly withheld or ignored even when any reasonable person could spot the flaw--little additions and subtractions that move the plot forward but don't really make a lick of narrative sense. Benefit of the doubt, however, suggests that the dismantling of the movie's intelligence was a committee process, because every aspect of the filmmaking suddenly drops in I.Q. at right around the same time. Evelyn Salt goes from mostly believable stunts to jumping around like Spider-Man, Noyce and editors Stuart Baird (Casino Royale) and John Gilroy (Michael Clayton) start chopping the scenes into smaller and smaller chunks, and the music by James Newton Howard (I Am Legend) jettisons any sense of subtlety or finesse, underscoring every moment for ultimate bombast. It's so dopey, it's almost like someone swapped in the final reel of a Steven Seagal movie and no one noticed. Seriously, I know there is some false nostalgia going around for bad '80s action movies, but some things fade for a reason.

I will give Angelina Jolie credit, she does manage to keep a straight face no matter how dumb things get. (She also looks great, even when we can't figure out how she managed to raid Julie Christie's Dr. Zhivago closet before getting on the Staten Island Ferry. I mean, whatever, she has to look like a Russkie for this reverse-Ellis-Island moment, or it'll never work!) Chiwetel Ejiofor never blinks either. Only Liev Schreiber has the good sense to be embarrassed. I'm convinced he flubbed a couple of line readings on purpose.

I also can't claim I ever really got bored. Even while the plot disintegrated, I still couldn't predict what was going to happen next. That in itself is something, I suppose. Not enough for a full-price ticket, though. Insert joke about moderating your Salt intake here.

Jamie S. Rich is a novelist and comic book writer. He is best known for his collaborations with Joelle Jones, including the hardboiled crime comic book You Have Killed Me, the challenging romance 12 Reasons Why I Love Her, and the 2007 prose novel Have You Seen the Horizon Lately?, for which Jones did the cover. All three were published by Oni Press. His most recent projects include the futuristic romance A Boy and a Girl with Natalie Nourigat; Archer Coe and the Thousand Natural Shocks, a loopy crime tale drawn by Dan Christensen; and the horror miniseries Madame Frankenstein, a collaboration with Megan Levens. Follow Rich's blog at Confessions123.com.