SALT is a big summer thriller that really, REALLY wants to be the next BOURNE franchise and nearly succeeds in doing so until a completely brain-dead third act derails the entire film. Fortunately, the movie is entertaining enough to warrant a big screen viewing and star Angelina Jolie does her absolute best with the material at hand, so all is not lost.

If you’ve seen the previews for SALT, you already know the premise. Evelyn Salt is a top CIA agent who’s married to a pretty great guy (an underused August Diehl) and seems to have a perfect life. Well, as perfect a life as anyone who was tortured by North Korean soldiers can have, but you get the point. Everything is good in Salt’s life. That is, until a Russian defector shows up at the CIA’s doorstep and names her as a sleeper assassin who’s going to assassinate the Russian pres in two days during something codenamed “Day X”. It’s at this point that SALT really takes off (we’re only ten minutes in when she’s named as a traitor) and it never looks back.

If there’s one thing that SALT does really right, it’s that the pace here is breathless. Once she’s named by the defector as being an a sleeper agent, the film takes off and propels itself flawlessly from one action set piece to the next. Even more impressive is that SALT also manages to squeeze in a decent level of characterization in-between the big action bits. Nothing Earth-shattering mind you, but enough that you actually manage to care about these characters and you’re interested in where they are going.

Interestingly enough, the big mystery that has been predominately featured in the trailers and promo material, the question of “Who is Salt?”, is actually answered within the first thirty minutes. And trust me, the movie doesn’t spell it out for you. There’s no hammering over the head or clear-cut moment where you realize what is going down. One minute you’re seeing Jolie apply a maxi-pad to a wound to stop the bleeding and in the next, you realize that not everything is quite as it seems. It’s a tricky moment, but director Phillip Noyce is a pro and handles it well. Even after you realize what is happening, the audience is still invested in Jolie and her plight. That’s some quality filmmaking, people.

Too bad the movie doesn’t stick to it’s guns and deliver on the promise of the first two acts. Strangely enough, SALT begins to derail after what is easily the best sequence in the entire film. There’s a shoot-out on a boat that not only manages to be exciting and push the envelope of what a PG-13 film can deliver, but it also a huge character scene, full of heartbreak and emotion. However, once the sequence is done, SALT kicks back into BOURNE mode and propels towards one of the most illogical conclusions to a movie I’ve seen in a long time.

That’s not to say the finale isn’t exciting because it is. Matter of fact, if you shut your brain off, you’ll have a damn fine time with the finale. There’s explosions, fights, double and triple crosses, a truly magnificent send-off for one baddie (I won’t spoil it, but you’ll know it when it happens) and nothing short of the fate of the entire free world is in the balance. It’s almost as if Noyce stepped aside and let Michael Bay film the last act, it’s that over-the-top.

Thing is, this isn’t a flick that needs an over-the-top ending. SALT needed an ending that made good on the promise delivered at the beginning. Not without spoiling anything, but once you’ve seen the movie and you realize what the final twist is, I want you to ask yourself one thing “If that was the final twist, then what was Salt doing there in the first place?”. The reality of the movie is that if that was what she was from the get-go, then she’d have bailed on the entire situation after the boat sequence. Salt would not have continued on and she certainly wouldn’t have been jumping down an elevator shaft like a spider monkey.

That’s really the biggest problem I have with the third act. Not only is it implausible from a plot standpoint, it’s absolutely ridiculous from a film standpoint. Jolie suddenly goes from being a calm and cool character to a ridiculous action heroine, complete with wire-fu, massive karate skills and the ability to maneuver around one of the most guarded and watched places on the planet without so much as being seen once. Even worse, the last act takes a character who was pretty awesome in the first part and turns them into a grinning super villain. And even worse than that, Andre Braugher, so amazing on HOMICIDE, shows up in the finale, delivers one line (I kid you not) and then gets gunned down. Who thought that was a good idea?

Okay, I realize that I’ve ranted a good bit about the finale and you’re probably wondering “How was the rest of the movie?”. Well, the first 2/3 of the flick (everything before the end of the boat sequence) is pretty fantastic. Jolie is at the top of her game here, delivering a very interesting performance that is far more than kicking ass and taking names. Liev Schreiber and Chiwetel Ejiofor are both spot-on as the CIA and FBI agents after her. The entire first 2/3 of the movie is almost a perfect blend of the spy and the “man on the run” genre. Completely engrossing, exciting, you couldn’t ask for a better movie to waste an afternoon on this summer.

Then that ending happens. Man, that ending screws everything up. I’m not sure if test audiences caused that or if someone else is to blame. Personally, I blame writer Kurt Wimmer. Dude did the same thing with LAW-ABIDING CITIZEN. Amazing first two acts, complete wet fart of a third one. SALT does the exact same thing. The first two acts are absolute gold, couldn’t have been better. But once the third act rolls around, implausible plot twists abound, the entire concept of the movie is altered and they completely rip off the ending of THE BOURNE ULTIMATIUM in the hopes that SALT will spawn a franchise.

It’s too bad really. Had they stuck to their guns, SALT might have been something really special. As it stands, SALT is a missed opportunity that, while definitely worth seeing for Jolie’s performance and those first acts, ultimately disappoints and fails. Four out of six adamantium bullets.