Unlike the previous three Terminator installments, the plot of Salvation doesn't revolve around Skynet, the A.I.-empowered computer system that controls the machine army, sending one of its soldiers back in time in an attempt to change the future. Instead, all of the action occurs in the year 2018, before Skynet has developed the ability to time-travel. But that doesn't mean it doesn't have a few surprises up its sleeve. In a development that John's mother/mentor/drill sergeant Sarah Connor (who does not appear to have a role in the film, one of the few elements from Terminator 3 that carries over into this installment) never foresaw, Skynet has been experimenting on surviving humans in an attempt to fuse man and machine. The resistance rescues one of these "hybrids," Marcus Wright (Sam Worthington), who resembles a normal person on the outside but underneath packs more iron than Iron Man. "The Marcus character is a real exploration of what it means to be human," McG explains.
"You can have metal bits and pieces running through your body, but it doesn't make you any less of a man. And the question is, where do you become a machine and let go of your humanity? I did a lot of thinking about Christopher Reeve and the idea that if you lose control of your four limbs or body, does it make you less human? Of course, the answer is no; many would argue that Chris Reeve became more human [after his accident]. So where does the soul reside, where does humanity exist? Not in your arms, your legs or your torso. That's what the movie is all about—the nature of what it is that makes us human."
In case you're wondering where the war is in this so-called war movie, don’t worry—McG promises that moviegoers will get plenty of bang for their buck. Rather than restrict the action to green-screen-lined soundstages, many of the film's biggest sequences were shot in the New Mexico desert and favor practical special effects—including real explosions and bullets—over CGI. "I wanted all of the action based in reality with a respect for physics and I wanted it to have a tactile reality for the audience. That's why we did so much practically, to really convey the difficulty of a world under duress. I didn't want clean, shiny Logan's Run Terminators. I wanted Children of Men/Mad Max Terminators."
The grimness and intensity of the film's world often carried over into real life, most notably when Bale was caught on tape yelling at the film's director of photography Shane Hurlbut for apparently interfering in an important shot. The actor's rant was later leaked to the public, leading to numerous news stories and even a few homemade remixes posted on YouTube. "That's the nature of a movie set," McG says now about the incident. "I've never made a movie where there weren't flare-ups. I encouraged an environment of intensity and hotheadedness led by me. I have a bad temper and am very passionate and want that level of intensity to show up onscreen at all times. And I want the best, most intense version of Bale, because that's what he's here to do. Besides, it was taken out of context and I think people understand that and it's largely come and gone without too much fuss. I do think it's a slap in the face to Hollywood that private material would be leaked. Movies are designed to only see the finished result."
As he puts the finishing touches on Terminator Salvation, McG is already looking ahead to the next chapter in what the studio hopes will be another trilogy. "I strongly suspect the next movie is going to take place in a [pre-Judgment Day] 2011," McG reveals. "John Connor is going to travel back in time and he's going to have to galvanize the militaries of the world for an impending Skynet invasion. They've figured out time travel to the degree where they can send more than one naked entity. So you're going to have hunter killers and transports and harvesters and everything arriving in our time and Connor fighting back with conventional military warfare, which I think is going to be fucking awesome. I also think he's going to meet a scientist that's going to look a lot like present-day Robert Patrick [who famously played the T-1000 in Terminator 2], talking about stem-cell research and how we can all live as idealized, younger versions of ourselves."