I’m a Star Trek fan from way back.  I enjoyed “Star Trek:  Beyond.”  Why am I not more enthusiastic?

Star Trek:  The Original Series (“TOS”) was almost purely episodic.  Each week, another new world or new civilization, a unique problem, a nonrepeating set of guest stars.  Each episode stood pretty much alone.  You could miss one and not be at a loss when you saw the next one, because nothing had changed.  The original “setup” was restored at the end of every show.

This wasn’t unique to Trek; it was the norm on television back in the 1960s.  “Situation comedies” were defined by a permanent “situation” that formed the basis of each week’s program.  Dramatic shows like “Bonanza” or “The Man From U.N.C.L.E.” used the same method.  No matter what happened in the course of one episode, things were back to normal by the opening of the next.  The reductio ad absurdum is “Gilligan’s Island.”  There was a melancholy certainty that no matter how hopeful things seemed, they were never getting off that island.

Of course this was never entirely true.  One of the Cartwright sons on “Bonanza” was Cartwritten out of the script and disappeared.  Chekhov joined the Enterprise crew in the second season of Star Trek and stayed on thereafter.  But mostly, the “initial conditions” for each episode remained the same.

What we did not see was long-running plot arcs or character development.  Each plot had to wrap up neatly in a single episode.  Characters and relationships were static.

It’s instructive to look back and realize how much this has changed.  TV series these days are expected to have long-term plot arcs, often spanning a season or more.  A series like “Chuck” might change the plot premise significantly from one season to the next.  And viewers today are addicted to mini-series (maxi-series?) with extremely long and complex plots, as in “Game of Thrones.”

As the Star Trek movies came out, it presently began to seem that we were essentially seeing series episodes, but stretched out to two hours rather than one.  It left a vague feeling of being cheated.

In a typical two-hour movie, there’s time for more leisurely plot development, and one expects things to happen.  Sure, there are long-running series like the James Bond movies that cycle back to the same scenario just as the old TV series did.  But that isn’t true of most movies.  Even sequels frequently find themselves starting at a new point in narrative or character development—which was a challenge for moviemakers who merely wanted to reprise the success of the original film.

If we pass in merciful silence over Star Trek I (“The Motion Picture”), the striking thing is that the next three movies did have a continuing plot arc.  I’ve heard that they were plotted as a coherent trilogy by Harve Bennett, and that does seem to be borne out by the movies themselves.

While Star Trek II, III, and IV represented remarkably different types of films, there was a continuous thread of action.  The Enterprise crew created the Genesis planet in II, returned to that planet and saw its collapse in III, and made their own return to Earth in IV.  With side trips, of course.

And there were character changes.  One of the things that makes Star Trek II the best of the Trek films is the impact of Spock’s death, around which the entire story is carefully constructed.  Of course fans were pretty sure even then that his death wouldn’t be permanent.  But the characters didn’t know that, and we got to see how this loss affected them.  And Kirk’s son David Marcus did die for good in III—though this new character’s death didn’t have the impact of Spock’s.

Star Trek V and VI, however, were unconnected stories riffing on the same traditional characters, and momentous as the writers tried to make them, there was a distinct sense of “back to the old grind.”  VII was somewhat unique, as the intersection of the TOS crowd with “The Next Generation” (TNG) characters.  But the following movies, VIII through X, were very like individual episodes of the TNG series.

The three films beginning with the 2009 reboot also strike me as standalone episodes.  The occasional attempt to tie them back to other storylines, as with the appearance of Khan and Carol Marcus in “Into Darkness,” is offset by the disconnection from all earlier stories stemming from the timeline change in the 2009 movie.

So this year’s Star Trek entry strikes me as okay, but it lacks the cumulative force of a long-term plotline—unless perhaps you take a strong interest in the desultory Spock-Uhura romance, which so far hasn’t gripped me.

By contrast, series that do have long-term plotlines and character developments, as in Star Wars and Harry Potter, can build up quite a head of steam—and corresponding viewer loyalty—through the accumulating drama of an extended story.

The fact that we now expect long-form plot arcs makes for an interesting countercurrent to some of the standard assumptions about today’s audience.

It sometimes seems that we have all been seized by a collective attention deficit disorder.  Writers are warned to “hook” their readers, not in the first page or even paragraph, but in the first sentence.  Communication packets have been reduced to 140 characters.  It’s easy to bemoan how rushed we all are, and how short our attention spans.

But at the same time, modern viewers take in stride a series of six or seven movies.  Harry Potter brought a generation of viewers through eight lengthy parts without blunting their appetite for more Potteriana.  TV series routinely carry on long-drawn-out developments.  Novel readers happily consume endless serials like the Honor Harrington tales, or the fourteen massive volumes of Robert Jordan’s Wheel of Time.  By today’s standards, the 1800-page Lord of the Rings, touted as a huge work in the 1960s, seems positively concise.

To my mind, this says something favorable about today’s readers and viewers.  We’re fond of the sound bite and tweet, yes—but we also seem willing to tackle much longer stories than in the olden days.  There may be hope for coherence and continuity yet.