Spoiler warning: Terminator Week may spoil the original Terminator, which you really should have seen anyway. Oh, and today there may be mild spoilers for the first trilogy of Dragonriders of Pern.Yeah, you heard me.

One of the reasons I love Terminator is that it’s not just a good action movie, it has a good sci-fi story. The dark vision of the future — the war machines grinding over a layer of human bones, children happily watching the fire they’ve made in an old TV shell — is compelling, but the actual plot is interesting, too.

I grew up loving time travel stories. I could probably blame Back to the Future for this, but let’s not let Star Trek off the hook either. In serious childhood conversations with my dad, I asked about how time travel worked (Hey, my dad knew everything. I probably thought he took a class in Time Travel at Caltech!). Based on the theories he outlined, I had to admit that a Back to the Future-style universe seemed unlikely, one where you could make changes, perceive them, correct them, et c. But it took a while for me to warm up to the Immutable Universe alternative.

Perhaps my first experience of the immutable timeline in fiction was in Anne McCaffrey’s original Dragonriders of Pern trilogy, where mysterious things have happened in the past, and the characters gradually realize they have the ability and the duty/destiny to go back in time and cause those events. It’s a tricky thing to write, but when it’s good it’s very good indeed.

And the original Terminator was one of those times. You can dispute me based on the movie you saw, but I’ve read the original script. In the original script, the reason they end up at the factory at the end is that Sarah wants to try to prevent the rise of Skynet by blowing up the company that will eventually build it. Reese thinks it isn’t possible to change the future, but she manages to drag him along. After the final fight, we see a manager of the company pocket a computer chip from the Terminator. It’s a perfect closed loop: Skynet is made possible by technology that came back from the future Skynet created. John Connor is made possible by the hot freedom fighter DNA he sent back from the future he saved.

Now, Terminator 2 used the reverse-engineering conceit, but one of the reasons my affection for it is tinged with regret (besides the fact the Kyle Reese dream sequence is a deleted scene! Oh, and that damn kid) is that it ruined the perfectly finished time-knot of the first movie. Sure, all the details in the original script didn’t make it into Terminator, but nothing in the movie contradicts them: closed loop. Suddenly in Terminator 2 you can change the future. The loop is open and frayed. Probably it made sense to a national consciousness emerging from the gloom of the Cold War, but I loved the austere fatality of the 1984 movie. It was an elegant little story, one that met the challenges of plotting in an immutable timeline admirably.