“I’ll be back,” Arnold Schwarzenegger said in the first “Terminator” movie. He had the title role but only 16 lines, with about a total of 80 words. But those three words have become a legend. It now appears he meant it more than we thought, as he appears four decades later in a fifth “Terminator” movie, with two more in the pipeline.

The storyline is about how a network of computers called Skynet took over and all but destroyed life on earth, except for a small group of rebels led by John Connor. Given the time travel that occurs in the films, they in effect act as their own prequels and sequels. This is more of a side-quel, presenting some of the same characters and events in a sort of alternate, butterfly effect universe. Some changes are explained, including why a robot that looks like Arnold Schwarzenegger now looks so much older than he did in the first one. (I didn’t say it was explained persuasively, just that they recognize someone has to say something about it.) Many changes are not explained, and I am not just talking about the fact that the characters are, other than Schwarzenegger, played by different actors.  Some of those changes are good. Some are not.  And some are just dumb.

Here’s a good one.  In the first film, we learn that John Connor has sent Kyle, his top rebel colleague back in time to protect Sarah Connor because the Terminator (Schwarzenegger) has been sent back to kill her before she can even become pregnant with Connor, to eliminate him so that he can never be born and lead the rebellion against the machines.  In this film, we see it happen.  John (Jason Clarke) explains that, as we already know but Kyle does not, Sarah is not yet the tough, resilient woman she will become by the end of #1 and really show us in #2.  She is “scared and weak.”  She is also, John tells Kyle, a waitress, though since Kyle was very young when Skynet took over and declared humanity a pestilence that had to be eradicated before it contaminated the earth beyond repair, he has no idea what that is.

But then we see Sarah (now played by “Game of Thrones'” Emilia Clarke, no relation to Jason), and she is not the frightened, inexperienced girl Kyle expected.  Plus, she has Terminator of her own (Schwarzenegger) who is protecting her, not killing her.

Even by the very low standards of blockbuster sci-fi, the mumbo-jumbo here is pretty over the top, with plot holes bigger than the school bus that hangs over the side of a bridge in one of the film’s showiest action sequences.  We have not quite reached nuke the fridge status yet, but we’re teetering on the brink with unanswered questions and outright subversion of some of the series’ core precepts.  And it is one thing to make reference to the earlier films; it is another to wink at them and at us.  Make a character we trust untrustworthy. Okay. Age the Terminator.  Well…okay.  Call him “Pops.”  Sort of okay. Have him fake smile.  Okay.  Have him keep a cache of sentimental tokens.  Not okay. This is not Pinocchio, and he is not going to become a Real Boy.

But hey, this is summer, and we don’t need think-y movies, right?  So  let’s drive right through those plot holes, enjoy seeing Arnold now fight a CGI Arnold circa 1984, hang that school bus off the bridge, and keep going, without looking back.

NOTE: Stay past the credits for a scene that will not surprise you about what’s in store for #6.

Parents should know that there is extensive and intense peril and violence throughout the film, just under the R level, with characters injured and killed and some disturbing images.  There is also some discreet nudity, and brief strong language, with a couple of mildly crude sexual references.

Family discussion: If you could go back in time to make a change, what would it be?  What is the best way to prevent a Skynet-type machine takeover?

If you like this, try: the first two “Terminator” movies