In that seminal science-fiction film, Sarah Connor was an ordinary woman targeted by a time-traveling cyborg (Arnold Schwarzenegger) because she would later bear the savior of all mankind. The cast and crew worked long nights, and Hamilton spent much of her role cowering or on the run. “It was hard on the psyche,” she said. “When I finished, I fought some depression and kept dreaming about the Terminator.”

What she hadn’t dreamed of was a sequel. Years later, when Cameron contacted her out of the blue to see if she’d commit to “Terminator 2,” Hamilton had only one request: Instead of playing the damsel in distress again, she wanted Sarah to go crazy. “I wrote it to the hilt based on her directive,” Cameron told me .

This version of Sarah Connor, locked away in a psychiatric institution, had war in her eyes and a body trained like a weapon. In order to play her, Hamilton would have to get into staggeringly good shape, since Sarah’s robo-apocalypse training included pull-ups and, eventually, bicep-straining shotgun pumps. There was just one thing: “I was six months pregnant when Jim came to me,” Hamilton said, “and I carry my babies big.”

Hamilton was still married to the actor Bruce Abbott when Cameron first floated the idea of a “Terminator” sequel; by the time he had returned with a finished script, Hamilton was mothering her newborn son, Dalton, and Abbott had asked for a divorce. It was hardly the ideal time to take on such a demanding action film, yet Hamilton saw it as an opportunity to pour everything she was feeling into Sarah.

“Having been left, I just needed to get up on my feet and be strong and do nothing but mother my child and get ready for this film,” Hamilton said. “You wake up all alone with your body and go, ‘Hmm, these aren’t hips anymore — they’re flanks.’ To give myself permission to be that powerful, strong woman was necessary for my survival.”

The result was one of the most indelible action heroines of all time, a muscular mother who fought like hell. “That character still isn’t normalized,” said Mackenzie Davis, who co-stars with Hamilton in “Terminator: Dark Fate.” “She wasn’t evincing this hyper-fashionable or hyper-feminine aesthetic of a time, so it’s allowed the Sarah Connor character to be this transcendent visual icon.”