Grade: A-

“A miracle is something that seems impossible but happens anyway.” So says Griffin, the quirky, quotable, and eternally-earflap-hat-clad psychic sidekick who joins agents J and K in the latest “Men in Black” installment... and I can't help but agree. After the colossal failures of countless other threequels — when will they realize that they can't just rehash all the jokes that were funny in the first one, “Pirates of the Caribbean” where-has-all-the-rum-gone-style? — it's sort of a miracle that “Men in Black III” is so entertaining. (Even though, yeah. The writers skirt plenty of uncomfortable corners by employing that handy-dandy, memory-zapping neuralizer flashy-thingy.)

Maybe I had just the right concentration of caffeine pulsing through my bloodstream to counteract any needling doubts about the three pillars of threequeldom. Or maybe I'm just way more nerdily into time-travel tropes than I thought. (“Star Trek IV: The Voyage Home.” Oh, man. Humpback whales and time travel.)

Either way, I liked this movie, and I'm not ashamed to say it. There's certainly nothing earth-shatteringly clever or inventive or even remotely logical about it — it's just fun in a loud, campy sort of way that evokes an enthusiastic middle school food fight. Director Barry Sonnenfield keeps scenes moving at a frenetic pace, with all of the gooey “Gremlins”-esque space creatures we've come to expect... A giant frowning blobfish. A creepy little spiderbot version of Voldemort's pet Nagini, who rapidly picks locks and purrs affectionately after a task well done. A spiky, betentacled baby turtle monster with big googly eyes who lives in a bowl of soup.

Here's the set-up: the bloodthirsty Boglodyte Boris the Animal escapes from prison and goes back in time to murder the agent who originally put him there. (Yes, girls, that's Jemaine Clement from “Flight of the Conchords,” looking a little less arresting than his usual part-time model self.) When Agent K (Tommy Lee Jones) goes missing, Agent J (Will Smith) embarks on a cross-dimensional journey back to the summer of '69 to set things right, where he encounters everything from racist cops and endearingly outdated “future” technology to Andy Warhol himself (err, well, not himself, exactly.)

Smith is his usual boyish self, and Jones is, of course, the craggy, deadpan antidote — albeit, we don't actually see a whole lot of him in this movie. Josh Brolin's “younger” incarnation of Jones is almost spookily spot on — in an amusing nod to those “city miles,” 44-year-old Brolin plays the tight-lipped, no-nonsense 29-year-old K with a twinkle in his eye that is in and of itself worth the price of admission. Blue-eyed Michael Stuhlbarg is quite endearing as Griffin, who muses with infectious wonderment about destiny and the infinite possibilities for the future. His presence adds an almost spiritual dimension to the film that culminates sweetly and surprisingly in the final act.