Either I'm getting dumber or the “Transformers” sequels are getting more coherent.

I say sequels because the 2007 film, the first live-action feature based on the cartoon based on the toy, basically “made sense.” It was silly but hewed, more or less, to what a major action film's story usually looks like. The second one went off the rails completely, but the Hollywood writer's strike makes a nice scapegoat. The third one, also, was a disorienting swirl of plot bafflement, but the final hour's quite striking 3D “Battle of Chicago” made for a palate-cleansing sorbet.

The point is, despite seeing all three previous “Transformers” movies I have no clue what they're about, or really any insight into the characters. But I do have a vague sense that the last one was “kinda fun.”

Luckily, that's all you need for part four, “Transformers: Age of Extinction.” The slate is wiped (good riddance, Monsieur LeBeouf), the nation is licking its wounds after Chicago's destruction (though the city looks well-repaired) and the Transformers have all gone underground.

The CIA (hissssss!) is hunting all of the robots-in-disguise, be they Autobots (good guys) or Decepticons (bad guys.) But actually, that's not true! They are really only hunting Autobots because the top cheese at the CIA (Fraiser Crane), working in cahoots with a Steve Jobs-type (Stanley Tucci), have cut a deal with one of the Cybertronian villains named Lockdown.

Lockdown, who has Lamborghini branding but, alas, does not have a Chico Marx accent, will give the human bad guys “the seed” if they get him the hulk of Optimus Prime. What's the seed? The seed is, and I'm joking far less than you may think, the intergalactic semen of “The Creators” that brought Cybertronian life into the Universe. (It resembles a small, chrome torpedo.) And where's Optimus Prime? Well, I'll tell you.

Optimus is hibernating in the barn of a junk collector/mad scientist/robotics expert deep in the heart of Texas. The part of Texas where there's corn and humongous American flags and ultra-thin hotties and it's always magic hour. The barn belongs to Cade Yeager, played by the Mark Wahlberg and his lack of Texas accent. While Mr. Wahlberg delivers many of his lines as if he's addressing animals, this iteration of the “Transformers” films features something no previous installment ever had – a lead actor with charisma and talent. For years we've been joking “the humans don't matter in these films.” They still don't, but when you've got someone you kinda care about, it helps.

Wahlberg's driving motivation throughout the film is to keep his blonde, tight-jeans wearing, 17-year old minx of a daughter chaste. It isn't going well, as she (Nicola Peltz, heir to the Snapple fortune) is dating an Irish race car driver named Shane (Jack Reynor). 17? Is that legal? Yes, it is, due to something called the “Romeo and Juliet” laws of Texas, and Shane actually KEEPS A COPY OF THIS LAW in his wallet. Way to go, Shane! You may now run for office.

Soon the Feds come to the farm to find Optimus and – BLAM! - the chase begins. There's another highway fight (again, Transformers do a lot of slo-mo cartwheeling and yanking hurled bodies to safety) and then, once Optimus gets the band together, they break into Steve Jobs' evil Transformers lab and – and then I dunno. There's a big battle in Chicago again, this time with a space ship, and then a big battle in Hong Kong. (Steve Jobs has a Transformers-making facility in China – if he doesn't brand them as “Sinobots” I don't know what I can do for him.)

The battles – the reason anyone would want to see this movie – are, for the most part, entertaining. There's a moment when giant steamships fall from the sky like rain. Stanley Tucci's cowardly technocrat wimpers and howls and is funny, in a broad sense of the word. The fighting robots look less like thrown cutlery than they used to; you can kinda follow what's happening. Whereas the last two movies had almost no character motivation, this one has a decent hook: find that seed. (It's also a bomb that will kill everyone.)

The dialogue is ludicrous, but when you see it at a good theater there are few pleasures in life like having your seat vibrate with the deep, resonant tones of Peter Cullen's Optimus Prime. Cullen's voice is a bonafide touchstone of this idiotic franchise – without him bellowing “Roll out!” these movies would truly lose a lot. I hope Michael Bay and Paramount are giving this guy a lot of money.

The other robo-voices are amusing, too: John Goodman plays a “give-'em-lead” bruiser with a robo-cigar and Ken Watanabe plays a samurai who calls Optimus “sansei” and talks about shame. There's another Autobot that wears a metal coat so when he zips around he looks like he comes from a cyborg version of a John Woo film. (Wikipedia tells me he was voiced by the same guy who voices Bender, but I didn't hear it.)

At the 2hr 15 min mark, when any movie like this should already be over, we meet the fan-favorite Dinobots. Yes, robotic dinosaurs, one of which is ridden into battle by Optimus Prime. You may applaud, if you are still awake.

I can not tell a lie. I had a fun, enjoyable (albeit long) night at “Transformers: Age of Extinction.” Keep in mind, I went with about ten colleagues/friends and didn't pay. That's how it is for me with all movies, but with something like this it really makes a difference.