As I watched “Men in Black: International,” I couldn’t stop myself from scribbling “holy biceps” onto my notepad. However, this observation was not about Chris Hemsworth, but rather his co-star, Tessa Thompson (though I later added a note about Hemsworth’s abs, lest he be left out). Yet sometimes, biceps and abs aren’t enough. Thompson and Hemsworth, having already proven their chemistry in “Thor: Ragnarok” and remaining unfairly attractive, buoy the latest entry of the “MIB” franchise with their game performances, yet for all of their appeal, the movie doesn’t do quite enough to merit its own existence.

The movie follows Molly (Thompson), a clever and determined IT employee who has dedicated her life to finding and joining the Men in Black after witnessing their agents wipe her parents’ minds as a child. Molly, of course, finds the Men in Black and convinces Agent O, a woefully underutilized but predictably great Emma Thompson, to let her join them. O sends the newly christened Agent M to the London branch of MIB, where she meets the foolhardy Agent H (Hemsworth). After some initial setup, an expendable alien gives ominous warnings of corruption in MIB’s London branch and assigns Agent M to protect a highly valuable weapon. This sends H and M (our dynamic duo, not the clothing retailer) on a globetrotting trip to Marrakech, Morocco; Naples, Italy; and Paris. H and M soon find out that the villainous alien race known as the Hive has resurfaced, despite their apparent defeat by H and his mentor, High T (Liam Neeson, also underutilized, but at least his character’s name is kind of funny), years ago. Now, the duo must finish the job and protect the weapon while also seeking the mole within MIB’s ranks.

The movie threatens to buckle under the weight of its own plot at times, which also includes encounters with H’s three-armed ex, Riza (Rebecca Ferguson), who deals illegal alien arms, Pawny (Kumail Nanjiani), a tiny alien who joins H and M’s quest, and other disposable characters. The amount of plot the movie must chug through often leaves its characters by the wayside; we’re supposed to feel something during H’s interactions with Riza, but mostly we just wonder why Riza is wearing a knockoff Sia wig. Pawny, at least, provides some hearty laughs. It’s a testament to Nanjiani’s comedic skill that Pawny comes off as funny rather than annoying, because he could have easily been Jar Jar Binks if done wrong.

It’s due to strong actors like Nanjiani that “MIB: International” stays afloat. Thompson shines, as she always does, making Molly immensely likable and sympathetic, though not as relatable as Will Smith’s Agent J from the original “Men in Black” — as a child, Molly reads Stephen Hawking’s “A Brief History of Time,” which most people have never touched. Hemsworth, playfully objectified in this movie, plays the bumbling James Bond type with more than enough aplomb. As Marvel has learned, the hottest Chris does his best work when he’s allowed to be comedic, and “MIB: International” plays that up to the Nth degree, giving only the briefest glimpses into Hemsworth’s ability to sell quieter moments.

While framed as high-stakes and poignant, the moments between some characters, especially High T and H, don’t land because the film spends insufficient time establishing their relationships. Furthermore, the script fails to explore the interesting parallels between the relationships of High T and O and H and M as the pairs deal with the interpersonal sacrifices the MIB must make. Instead, the work is left to the actors, who can only do so much.

The action set pieces are engaging enough but nothing special, though there is a humorous — albeit unsubtle — moment when Agent H wields a hammer (though it is much smaller than Mjölnir). The Hive provide some engaging visuals, at least. When we first encounter them, they appear as small, glimmering humanoid nebulas — I only wish we had gotten to see more of this form. They soon acquire human bodies in twins Laurent and Larry Bourgeois, professional dancers who demand attention whenever on screen and almost make up for the lack of nebular visuals. The Hive were far and away the most arresting visuals in the film, but there should have been more competition for the top spot, especially in a movie about aliens. Though it would be fine for the action scenes and visuals to be deemphasized if character beats were elevated, as it stands, nothing in “MIB: International” really gets the attention it deserves. Instead, viewers are left with half-baked characters and a movie nowhere near as clever as the original.

Still, none of these flaws are quite enough to completely sink the film. Had there been different leads, the tune of this review might have changed, but “Men in Black: International” found such a ridiculously attractive, solid pairing in Hemsworth and Thompson that it’s hard to hate. It’s also hard to love, but that doesn’t mean it’s not an entertaining diversion for a summer afternoon.

Grade: B