My friend and I have a saying about science fiction: Dead is not dead.

I wished I had remembered that before I got all tweaked about Derek Reese getting killed off on Terminator: The Sarah Connor Chronicles. Guess who showed up alive and well in last night’s season finale, thanks to a time-traveling John Connor?

Uncle Derek! Yeah!

Not all science fiction abides by the “Dead is not dead” concept, but a lot of it does. Sometimes it’s through time travel (as was the case with Terminator—travel to a time where Derek hadn’t been shot and, voila!, there he is). Sometimes it’s through technology (cloning, Replicator technology, and Cylon technology kept dead characters around on both Atlantis and Battlestar Galactica). Sometimes it’s through powers and forces beyond our human comprehension (I lost track of how many times Daniel Jackson came back from the other side on Stargate: SG-1). And sometimes you don’t know exactly why the dead aren’t dead, but you don’t care—you’re just happy they’re not dead (Lost!).

So, they killed off my favorite character on Friday night on Terminator: The Sarah Connor Chronicles.

I'm going to miss you, Derek Reese!

It happened suddenly. One moment Derek Reese--brother to Kyle Reese, beloved and revered icon in the Terminator saga, and uncle to John Connor, humankind's only hope against the machines of the future--was there; the next moment he wasn't.

Producers, I'm just going to put it plainly: I think you've made a huge mistake.

The show had been fumbling around in its earlygoings, trying to find some emotional grounding in the midst of the time travel, the death and destruction, the relentless pursuit by killer cyborgs. And the emotional pull wasn't coming from where you might hope it would come from--Sarah Connor. Honestly, Sarah Connor has only managed to look crabby throughout the series. I get it--I suppose if I were pursued by killer machines and my son was in constant jeopardy, I'd be crabby too. It might be reality, but it makes for very dull sci fi.