JOPLIN, Mo. — Summer movies are often very similar. Though the packaging may change, the contents don’t: Heavy special effects, light character development, lots of explosions, little plot.

It’s a formula that has been honed through many seasons, tried and tested and refined to the point where it’s as if films have just fallen off of an assembly line. It takes a director with some clout to be able to challenge this model, and very little slack is given when they fail.

When they succeed, as Christopher Nolan has done several times from “Insomnia” to “Inception” and every Batman in between, it is looked at as the exception, and filmmakers quickly slide back into the safe ruts that they have carved out, where we see the likes of “Battleship.”

While this formula can produce entertaining escapism, when directors hew too closely to the status quo, the results can come off as bland, derivative or dull. This is why I worried about “Men in Black 3.”

The film, which started shooting before the script was finished, is an unnecessary sequel to 2002’s “Men in Black 2,” which was an unnecessary sequel to the original.

The first “Black” movie was a fun distraction, a lightweight film that highlighted the swagger that vintage Will Smith used to be able to pull off. The sequel was an atrocious copy of the original, lacking its originality and charm.

This time around, director Barry Sonnenfeld creates what should, in theory, be impossible with a star with the wit and charisma of Will Smith and a veteran actor like Tommy Lee Jones: a boring and lifeless film.

 This time around, Boris the Animal (Jemaine Clement) has escaped from a maximum security lunar prison to seek revenge on Agent K (Jones) for costing him his left arm and his freedom. To do this, he must travel back in time to kill the young K before he can imprison him, thus re-writing history.

He succeeds at this, leaving everyone else but Agent J (Smith) with no memory of K.

How does J remember a past that never took place, you might ask? You got me. Screenwriter Etan Cohen tries to explain it away, but the logic is so convoluted that it collapses in on itself.

The idea, I suppose, is that the viewer will allow some good will to the characters that they have grown to love. Unfortunately, for me, at least, that good will was exhausted by the previous film, so I spent a good portion of the film analyzing how improbable the scenario is.

 J then goes back in time to the day before Boris has gone back in time in order to kill Boris before he can kill K before he can imprison Boris. Still with me?

I won’t spend too much more time picking at the plot, because it begins to unravel before the viewer even gets a chance to tug at the loose threads.

It is certainly the weakest point of a fairly weak film, and as the foundation it crumbles under its own weight. It builds to an improbable ending, and the scene meant to stir emotion and explain away Agent K’s cragginess highlights the lazy or indifferent screenwriting that went into this film.

I won’t give this ending away, but it’s safe to say that it would negate the relationship between the two agents, as well as much of the history of the first two films, if it were to be true. It also portrays J’s father as a wholly irresponsible dad who seems unconcerned with his son’s safety.

Smith, who hasn’t been on screen since 2008, seems content to coast on previous success, phoning in a performance that seems worn and weary. He slips right back into his black suit, certainly, but it’s beginning to look threadbare.

Jones is obviously saving up for retirement, or perhaps hoping to get financially stable enough to never have to do another of these films. He bookends the film, playing the modern-day K.

When J jumps back in time, he deals with the younger K, an inspired Josh Brolin doing his best Jones impersonation. It is clever and entertaining, the best part of the film, but since most have already seen it in the previews, the novelty wears off quickly.

Clement’s Boris is one of the least intimidating feeling villains on screen for a while. Special effects are used to try to ratchet up his menace, but between his cartoony growl and his parasite spewing hand, he might as well been lifted from a Saturday morning cartoon.

“Black” is precisely what can go wrong when Hollywood plays by formulas and doesn’t take any risks. It is an unnecessary and unenthusiastic clone of a better original, lacking the fun that the first possessed, hoping to coast by on special effects and an inattentive viewer.

Sonnenfeld shows why he has spent so much time working television lately, and Smith has me hoping for another extended break from the big screen. It is worse than a bad movie. It is a boring one.