Keeping in mind that "Men in Black 3" had a notorious journey to the screen, fraught with delays, hiatuses, an unfinished script, a very big, very controversial movie star trailer for Will Smith, and a runaway budget of $215-million that led Sony Pictures to consider cutting their losses and shutting the production down, it's a near-miracle that the finished film isn't more of a disaster than it is. Arriving in theaters ten years after the briskly messy "Men in Black 2" and fifteen since the mediocre 1997 original, this second sequel is perhaps long in the tooth, but it's also, surprisingly, the most soundly written, actually taking the time to develop the relationship between alien fighters Agent J (Will Smith) and Agent K (Tommy Lee Jones) beyond the peripheral surface. While this character uptick is much-appreciated, "Men in Black 3" is still left wanting by a convoluted time-traveling plot that rarely takes advantage of J's fish-out-of-water circumstances and a villain who is never nearly as indelible as in his icky, perverse introduction.

When Boris the Animal (Jemaine Clement) escapes from intergalactic prison Lunar-Max and heads for Earth, he has one goal in mind: to seek revenge on Agent K (Tommy Lee Jones) for the severed arm he suffered at Cape Canaveral forty-two years ago. Not satisfied with getting back at him in the present, Boris travels back to the time of the incident, in July 1969, hoping to kill K and rewrite history. Hot on this goopy, spike-shooting alien's trail is K's trusty partner at the top-secret Men in Black organization, Agent J (Will Smith). It is there in the past that J befriends the younger, decidedly happier-go-lucky K (Josh Brolin) as he works to save his life and get to the bottom of the distinct personality transformation that has occurred in the intervening years.

When the first "Men in Black" was made, it was based on a screenplay by a single person, Ed Solomon. For "Men in Black 2," writing duties were shared by Robert Gordon and Barry Fanaro. Those were quainter times. With the graying "Men in Black 3," scribes have once more been doubled to four—Etan Cohen (2008's "Tropic Thunder"), David Koepp (2009's "Angels & Demons"), Jeff Nathanson (2011's "Tower Heist"), and Michael Soccio (TV's "The Fresh Prince of Bel-Air"). With any luck, "Men in Black 4" will arrive in 2027 with eight credited screenwriters and an 80-year-old Tommy Lee Jones being wheeled around while blasting alien butt. Such is the wild and wacky world of Hollywood, where too many cooks in the kitchen is most major studios' tried-and-true specialty.

Initially envisioned as a goofier take on alien invasion pics, the series goes through a slight metamorphosis with "Men in Black 3" toward action over comedy. To be sure, there's still plenty of humor (very little of it funny, save for Agent K's chilly, insensitive eulogy to late MIB boss Zed, previously played by Rip Torn), but in realizing that the budget is astronomical, director Barry Sonnenfeld (2006's "RV") has, perhaps wisely, decided that some bigger, more exciting set-pieces were called for to put said money on display. Thus, there is a rousing, stunt-heavy shoot-out in a Chinese restaurant run by aliens and serving them on the menu; a dizzying, almost tickling drop from a NYC high-rise that breaks the space-time continuum; and a flashy climax set at the Apollo 11 launch in Cape Canaveral. These scenes are diverting enough that they just might do the trick in neuralizing viewers' memories of how very '90s the "Men in Black" movies seem today. First, though, they'll have to draw them into the theater.

Will Smith (2008's "Seven Pounds") and Tommy Lee Jones (2011's "Captain America: The First Avenger") are in upstanding form as Agents J and K, their opposites-attract shtick on prominent display. Whereas their characters often went through the motions in the other two pictures, here they get the chance to start to explore the bond between them, leading to an unexpected moment near the end that would be touching if their development hadn't come so late in this series' proceedings. Jones is especially sly as he plays up K's grizzled lack of emotion and the heart hiding beneath the surface, but he disappears for a good hour stretch in the middle as Agent J goes back to 1969 to stop Boris' evil scheme. 44-year-old Josh Brolin (2010's "Jonah Hex") plays the 29-year-old version of Agent K ("You've got some city miles on ya'," Agent J observes when he learns how old he is) and is a dead ringer for a young Jones in both looks and speech. As good as Brolin is, this section is where the film loses its way, overlooking the comic potential of a very modern J being transplanted to the '60s. As is, the movie's version of this decade might as well be the twenty-first century for as indistinct as it's designed and portrayed. Meanwhile, as creepy as Boris is in the stylish first scene, complete with a slithering, French-kissing tongue and tiny aliens that do his bidding before getting tucked away in his body parts, Jemaine Clement (2010's "Dinner for Schmucks") is mostly relegated to the sidelines thereafter. Like Lara Flynn Boyle's villainess Serleena in "Men in Black 2," he's established and then given nothing to do.

Having watched the three films only days apart from each other, "Men in Black 3" is the best of the trilogy—though not enough for a rating upgrade. Sadly, said trilogy has never been more than pedestrian sci-fi comedies without the ambition to match their intended size. Lacking in danger and stakes, the films present standard narratives involving bad guys who will inevitably be defeated by the end and good guys whose lives never truly feel the least bit threatened. Lightly toned and with hardly a shred of darker sensibilities, they're frivolous larks and nothing more. "Men in Black 3" ups the ante ever so slightly by incorporating some fireworks and daring to the typical gags, but it's still more often than not no great shakes. By the end of summer, audiences will be asking the same question: "Men in Black who?"