"Jessie's goal is to kill John. I agree that she's there because many in the resistance are unhappy with John's relationship with the machines."

"I think Jesse either went back to kill John or kill Cameron. Or maybe even both. Perhaps she knows something about the future that Derek doesn't know. "

"Tthey would have showed Cameron in the pictures that Jesse swept underneath her bed, if she was a possible target."

"Personally i think she might have come back to get away form the war and she might be spying on them because she misses Derek and wants to see how John is becoming the future leader and mabe it will turn out that she wants to help them and give advice on what to do and don't do.
"

"No, Jesse is not a terminator! That's getting to be the excuse for everything. She's human until proven otherwise, OK? But we got some interesting info in the last episode: Jesse apparently comes from a different dimension or universe than Derek does. Because Derek says he doesn't remember the things that Jesse remembers, about his capture and torture and interrogation. Derek says he's done things that may have changed history. Quite possible! Like killing Andy Goode! So now we have humans coming back through time from multiple dimensions...or is it just one dimension, that has now changed? Is the future different, now? (If so, it sounds worse to me!) So if Jesse is truly human, and the future has truly changed...what does that mean???"