Robert Patrick has such an intense, intimidating stare that it basically landed him the iconic role of the T-1000 in Terminator 2.

The then-30-year-old actor trained multiple times a day so that onscreen, in addition to his acting, he could sprint without breathing hard afterward and fire a handgun so quickly, it was practically fully-automatic.

With Terminator 2: Judgment Day returning to theaters with a 3D rerelease next week, the accomplished film and TV actor granted an interview to Heat Vision to discuss how he landed the role in the classic 1991 sci-fi/action movie, the scene he enjoyed filming the least, and the training that goes into making a man into a machine.

Patrick starts off by dropping a bomb.

“Billy Idol was set to do the role of the T-1000, as I understand,” Patrick told Heat Vision. “I can tell you that I saw Billy’s image when I went to Stan Winston after I got the role. Unfortunately, he got into a motorcycle accident and busted up his leg, so he wasn’t able to physically do what the role demanded.”

After Idol was out, word got around that director James Cameron was looking for a villain for his follow-up to the popular 1984 film The Terminator.

“My agent sold me to the T2 casting director (Mali Finn) as a cross between David Bowie and James Dean,” Patrick said, laughing, “So, I was trying to create an intense presence while I was sitting with Mali. I had this intense stare, which she liked.”

After working with the casting crew on some movements, which Patrick described as “insect-like,” he got a call from Cameron to come in and do a screen test. The rest is history.

“It was just one of those moments when everything came together at the right time,” Patrick said.

Once cast as the liquid-metal killing machine, it was made clear by Cameron that Patrick had to be in top-notch shape for the role, not gigantic like protagonist Terminator Arnold Schwarzenegger, but lean, fit, and fast.

“I trained four times a day and physically got myself into it,” Patrick said.

The T-1000 ran a lot in the film. Not just ran, but went at full force and then would stop, showing no signs of exertion. That wasn’t easy to achieve, Patrick said.

“I did it like a sprinter would: I locked eyes on a target and focused so there was no wasted energy,” he said. “When done, I would clench my jaw, no mouth breathing, only through the nose and no expression because the character would not be straining.”

Patrick was so fast, he ruined one take when the T-1000 easily caught John Conner, played by Edward Furlong.

“The first big chase sequence we did at the mall before I take the semi, I caught John!” Patrick said. “And I was like, ‘What the fuck do I do know?’ And Jim was like, ‘Jesus Christ! How fast can you run?!’ And I said I didn’t know. So they had to crank up the speed of John’s dirt bike.”

Having a huge heart for animals, Patrick said he was not a fan of the scene (cut from the theatrical version, but on the DVD) in which the T-1000 kills John’s dog.

“As a animal lover, that was a little difficult to shoot, but it makes total sense — a predator relentlessly tracking someone down and this thing was in the way,” he said.

In addition to being in top physical condition, Patrick had to master a Beretta 92FS, the popular military and police sidearm.

When the T-1000 first encounters John Conner and the T-800 (Schwarzenegger), the ruthless machine unloads a 16-bullet magazine at lightning speed, then reloads just as quickly without looking.

“I worked with [weapons master] Harry Lu a lot,” Patrick said. “Jim told me I had to be extremely proficient. I had to work on squeezing the trigger as fast as I could, locking eyes on Arnold down the hall, and dropping the magazine without looking and being able to grab a new magazine and reload instantly, also without looking. I had to practice and practice and practice until I got it. And the thing that I added, and I was proud of, is I did it without blinking.”

Terminator 2: Judgment Day 3D will be released in theaters Aug. 25. Patrick said fans are going to be delighted.

“I got to see it in 3D in Jim’s screening room,” he said. “I got immersed in the movie because I have only seen it a few times. I sent Jim an email and told him of all the films to make 3D, this was a great example of taking an almost perfect film and making it even better. It is really cool, done in a great way.”

In addition to starring in the CBS drama series Scorpion, Patrick has a new film coming out, Last Rampage, in which he plays “the darkest character I have ever played in my life.”

The film, directed by Dwight H. Little, is set in 1978 and tells the true story of the infamous Arizona State prison breakout in Florence.

“The man I play, Gary Tison, is the devil incarnate,” Patrick said. “He is a man who wants his freedom and he is willing to step on his own children to get it and kill anybody to get free. The heart of the story is betrayal.”

Last Rampage is out Sept. 22.

This article originally appeared on the Hollywood Reporter.