This year marks the 31st anniversary of the original Terminator movie, and the 30th anniversary of another time-travel classic: Back to the Future. It’s all too easy to imagine Marty McFly jumping out of his DeLorean after a jaunt to 2015, reporting in disbelief that we had high-res 3D film technology with computer-generated effects that are indistinguishable from reality, and what were we all lining up for? Terminator V, starring a 67-year-old Arnold Schwarzenegger who’s still grinning awkwardly and spouting the same catchphrases.

Of course, the event Marty couldn’t have predicted, the event that caused the future to take a path radically different than anyone in 1985 would have expected, was the release of Terminator 2: the 1991 action masterpiece that vaulted Schwarzenegger’s sturdy killing machine from B-movie villain to A-list cinematic idol. Brilliantly, series creator James Cameron flipped the script and turned the Terminator into a hero; my brother surely isn’t the only Gen Y guy who gets ribbed about how the movie’s ending made him cry.

Two disappointing sequels later—one with Schwarzenegger, one without, neither with Cameron—we’re back in the thick of it with John Connor, the man who will lead humanity’s successful revolt against the machines circa 2029 if (a) he manages to stay born and (b) time-traveling envoys fail to prevent the machines from ever rising. As Genisys opens, we seem to have finally come full circle as we watch the warring factions dispatch their chosen knights to 1984, where—as we remember from the first movie—Schwarzenegger’s Terminator will attempt to kill John Connor’s mother Sarah before she can conceive, while good cop Kyle Reese valiantly does his part to keep her alive and facilitate her fertilization.

The first half of Genisys is the film’s most rewarding, as director Alan Taylor and co-writers Laeta Kalogridis and Patrick Lussier propel us through a version of the first film that gradually deviates from what we thought we knew. What starts out as a mass-market Inception, though, eventually turns into something more like a retread of Terminator 3, which was itself a retread of Terminator 2—with Schwarzenegger battling newer, more dextrous terminators. (I suppose that should be Terminators, since we learn here that the nefarious Skynet has been privatized as a corporate entity that would in no conceivable future history have failed to protect its intellectual assets along with its physical ones.)

Except for Schwarzenegger, the story’s principal characters have been recast. As John Connor, the itchy Jason Clarke is the latest adult actor to try and fail to be as obnoxiously watchable as Terminator 2‘s young Edward Furlong. Reese, who was first played by the fallen angel Michael Biehn and then beatified as Anton Yelchin, is now canonized as the blandly hunky Jai Courtney. Sarah Connor is now played by Emilia Clarke, a Game of Thrones star who goes from Essos to Esso as she trades her noble steeds for various means of combustible conveyance. Clarke wears tragedy well, but it’s impossible not to miss Linda Hamilton, who met injustice not with a bravely suppressed pout but with heavy artillery and gleaming biceps.

Much of the gravity of Terminator 2 came from Hamilton’s convincingly crazed performance; along with Sigourney Weaver in Cameron’s Aliens, Hamilton became one of the late 20th century’s most influential action heroines. One might count it as a feminist triumph that female fighters no longer need to look like Rambo to seem credible when slinging bandoliers, except that the latter-day Sarah Connor is a vastly less interesting figure—wrapped in layers of male protection, she’s gone from a powerful and protective mother to a sex object who endures constant speculation about when she’s going to “mate.” She cringes at this, and so do we.

For the first time in the Terminator series, Schwarzenegger is allowed to show his age, which is explained in the story’s continuity (such as it is) via developments that involve both the machines’ repeated attempts to do the smart thing by nipping their enemy in the bud; and the humans’ continued preference to make things as difficult for themselves as possible by jumping to the precise moment when their foes are at their strongest and the time to forestall doom is most limited.

What differentiates Genisys from the long list of recent movies that have aging actors throwing grenades—without, miraculously, throwing their backs—is its wryly elegiac tone. The Terminator’s “I’m old, but I’m not obsolete,” a line that at first sounds triumphant, is neatly twisted into a bleak commentary later in the film when a young ally throws it triumphantly at Schwarzenegger and he snaps back, “Not yet.”

Though Richard Attenborough’s passing is obliquely acknowledged in Jurassic World, and though the new Mel-less Mad Max might inspire one to contemplate the fate worse than death that’s claimed Gibson, the great irony of this summer’s blockbuster reboots is that it’s Schwarzenegger’s resurrected robot who most insistently calls upon us to observe the passing of time.

As the Terminator and his escorts hop from 2029 to 1984 to 2017, Taylor’s camera keeps coming back to Schwarzenegger’s weathered face, as if to remind us that whatever devices we cook up, time is not infinite and we should make the most of what remains. Though Taylor can’t make as much of two hours with the Terminator as Cameron did, Taylor nonetheless has crafted a strangely compelling film: a sort of memorial service for Schwarzenegger to inhabit in the form of his most unexpectedly sympathetic character.

– Jay Gabler