I have never seen a whole episode of any of the series. Which even than was only once or twice. I never new of it growing up but I know the basic premise. What I did see was hard for me to grasp but I have never made a serious effort to try. I am starting to think I finally should because half my Facebook friends are fans. A big question I have always had is it really a time travel series? I am a time travel fanatic. But mostly about exploring history. Yet the show seems to be more about fighting aliens. Or am I wrong?