The T-800 is ridiculously cool. It wears a biker jacket and sunglasses. It tells people it’ll be back. It hunts down the future mother of the future leader of the human resistance with a calm detachment that suggests it’s in control of the crisis even when the fate of all Skynetkind hangs in the balance. Arnold Schwarzenegger gave that robotic character charisma and a handful of catch phrases that ensured The Terminator would stick in our memory.

But the first two movies work because of Linda Hamilton.

Now, after being away from the franchise for 25 years, Hamilton is reportedly returning for the sixth movie, which will be produced by James Cameron and directed by Deadpool‘s Tim Miller.

The Terminator models are action figures, and Sarah Connor is the real star. That’s partially because the T-800 is a walking plot device. It exists in the story and on the screen for the sole purpose of killing Sarah, which means kicking the plot off and re-igniting it as long as it continues to trudge forward with murderous intent. T-800 has no inner life, it has no other purpose, it cannot be bought off with ice cream. It’s a fleshy script mechanism–which makes Schwarzenegger’s elevation of the figure to icon status all the more impressive.

Without Sarah, though, there’s no reason for the T-800 to be there. Without Sarah, there’s no reason for this movie or the franchise to exist at all. In running for her life, solving the mystery of why this machine is after her, and trying to grapple with the psychological damage of facing down a future you know will be horrific, she has all the choices to make. She has the only main agency.

Hamilton’s dedication to the character is absolutely fascinating, especially when you consider the kind of status a sci-fi flick about a robot from the future held in the early 1980s. It was a genre just emerging from schlock status with help from films like The Terminator and pioneering performances like Hamilton’s. She took a figure that could have been a hollow bombshell endlessly bouncing away for her life and grounded Sarah with genuine terror, urgency, and realistic awareness. It’s her journey from all-American waitress/nightclub enthusiast to world-saving badass. It’s her finger on the button that crushes the T-800 in the hydraulic press.

Maybe even more importantly, it’s Hamilton’s expression of Sarah’s drastic change that anchors Judgement Day. Yeah, Schwarzenegger gets the catch-phrases, and Robert Patrick got to turn into liquid metal, but Hamilton’s escape from the insane asylum is one of the most impressive, memorable sequences of the entire franchise. How’s that possible when the franchise stars powerful machines from the future?

It’s because the action is fierce and clever, and because we care deeply about her safety on a personal level. We need her to escape. We also know that she’s a sane woman getting out of a mental institution where she’s about to run into something (a good guy Terminator) that could drive her crazy. Plus, it shows off how far her character has gone in the course of two films. That’s really the wildest part of these movies; the central question is whether or not each of us everyday people would have the strength to survive the first film and the dedication to endure the second. The reveal of Sarah in the hospital, sinewy, doing chin up after chin up, is shocking. Her evolution is drastic and profoundly powerful. When the attendants hit her, all you want is for her to break out and save the world from itself.

Sarah Connor is the engine of the franchise, and Hamilton’s absence from it has been noticeable over the past 3 films. They’ve tried to replace her (in spirit with John’s future wife Kate Brewster in T3, and directly with a different kind of Sarah played by Emilia Clarke in the weirdly overlapping, retconned Genisys), and it simply hasn’t worked. That’s because Hamilton’s Sarah is the heart and soul of the franchise. Replacing her would be like replacing Schwarzenegger. We’ve gotten tastes of both, and neither have worked.

Hamilton’s inclusion doesn’t mean the newest incarnation currently in the works will be better than the last 3 films, but it certainly means they’ve fixed a fundamental problem. “There are 50-year-old, 60-year-old guys out there killing bad guys,” Cameron said when announcing the casting, “but there isn’t an example of that for women.” He also announced that they’ll be looking for a new young woman to act as the centerpiece for the film. That’s a head-slapper, because he’s already got a centerpiece. The urge to bring an ingenue into the picture to carry the next three films is a classic one, but the success of this next Terminator movie may hinge on whether they can treat Hamilton and Sarah Connor as the key to the franchise that she is.

Need More Terminator News?

• Watch Arnold Schwarzenegger’s son recreate a T2 scene
• Schwarzenegger still wants to make a Twins sequel
• The confusing timeline of Sarah Connor in Genisys