Just started watching Continuum... a Canadian sci-fi TV show about a "cop" and some "terrorists" from 2077 who get transported back to 2012.
It's pretty good (the cop is Rachel Nichols, Scarlet from the GI Joe movie) but it reminds me of Time Cop (the TV series spawned from the movie of the same name). Or, if any of you remember, Time Trax, a TV show with a similar premise. The reason why Time Trax sticks out to me is it had this martial art called Mosh Ti and a thing that the protagonist could do called "time stalling" where he visually sees things faster than normal so it enables him to fight better.
All these shows have to deal with the idea of if you change things in the past, do you affect the future... or the whole Terminator explanation that whatever you think you change in the past, it was meant to be and is actually required in order for the future to happen as it does.
Time travel is always a tricky proposition, the Fringe finale generated some questions because they traveled to the future to change the future in order to change the past (huh?). Even Looper's explanation of time loops didn't really make sense.
I do like the neatness of Back to the Future where they explained that any divergence in the past breaks off and causes a new timeline resulting in multiple universes thus preserving original timelines.
But I'm not really on board with the multiple timeline theory (which was also a variant in the movie Timeline) so I prefer the whole Terminator paradigm, that changing the past won't markedly change the future no matter what you do (which was the case in the Time Machine movie with Guy Pierce). The Shatner Star Trek stuck to this theory ("How do we know he didn't invent the thing?" when Scottie gave the scientist the formula for transparent aluminum) while the new Pike Star Trek does not.
Back to Continuum, they tested that theory by targeting ancestors of the people who traveled back in time. They even killed the grandmother of one of them but he remained in existence, so I think they are sticking to the "can't change the future" paradigm although that effectively kills the endgame of the terrorists as their whole goal is to change the past to serve their needs.
Bah... time travel is a conundrum.