Back to Dr Who/Torchwood
OK, I know this is the place for Doctor Who and Torchwood questions :)
So my wife and I have been watching Torchwood (just started season two), but I have not watched much Doctor Who - only up to episode 7 or so on the first season of the latest incarnation.
I know Torchwood is a spin off, so how much of the stuff we are exposed to in Torchwood are things we are supposed to know from Doctor Who, and how much is just an unknown mystery?
The first episode from season two, where the person who had a past with Captain Jack came out of the rift was what prompted this question.