With the “Deadpool” director at the helm, James Cameron’s groundbreaking science fiction series gets new life.

After three limp sequels that failed to carry the franchise effectively into the future, finally, they get it right. By bringing back Linda Hamilton as Sarah Connor, this sixth entry has real weight. Merely recasting the role of Connor wasn’t enough, Hamilton has a special spark, and in “Dark Fate,” it’s a kind of magic.

The story might seem familiar, but it’s not tired or stale. The screenplay credited to three writers (David S. Goyer, Justin Rhodes, and Billy Ray) knows the original Terminator mythology perfectly. In the future, the machines have taken over, and a small group of humans fights back. But the artificial intelligence has a secret weapon, time travel. And a new terminator, the Rev-9 (played coldly by Gabriel Luna), has been sent to the past to kill a young woman named Dani (Natalia Reyes). Not to be undone, the humans have their secret weapon in the form of the mechanically enhanced Grace (a badass Mackenzie Davis). The plan is to keep Dani alive.

Linda Hamilton is back and the franchise is all the better for it.

Of course, Grace can’t do the job alone, especially given the liquid metal abilities of a non-stop killer Rev-9. That’s where Sarah Connor (Hamilton) comes in to do what she does best: kill terminators. Along the way, they might just run across an old T-800, and that means we get Arnold.

Except for “Terminator Salvation,” Arnold Schwarzenegger has been a large part of every sequel. But aside from the first two films, directors underused the charismatic action star. Maybe he was distracted during his “governator” days. But here the big guy gets a new character arch, and he’s funnier than ever before. Even at 72, Schwarzenegger is a physical specimen, whose muscles are only part of his presence. He still has the intimidating stare, and pairing his stoic robot with a more organic, emotional version in the form of Grace is a good contrast. The lanky Davis holds her own well, both physically and emotionally.

Mackenzie Davis plays a new kind of machine.

But the foundation of this picture is Hamilton, a terrific actress that, for some reason, has faded from view. In the stirring opening title sequence, we see her in a scene from 1991’s “Terminator 2.” Sarah Connor is in the mental hospital. And we see how she’s changed in the years since the first movie. It was striking then. Hamilton, who famously changed herself physically for that role, plays Connor hard, both body and soul. She’s is a killer and as scary as anything from the future. This flashback bridges the 35-year gap between “T2” and “Dark Fate” perfectly.

A good team!

“Dark Fate” is impressive, but the action sequences, which are just fine, aren’t the reason to see the movie. It’s all Hamilton, reprising the role that helped make her career. And this time, Connor’s a grizzled veteran with an even bigger ax to grind than ever before. She carries a big stick too, toting around a host of weapons, expertly putting them to work. When she and Schwarzenegger are on screen together, I got a lump in my throat. And I’ll bet that I’m not the only one.