I loved the first series, but am struggling a litle bit with the second. The big gap between seasons didn't help and I had to go and read a summary of all of S1's episodes to remind myself what had happened.  I still have moments when I squint at the screen and ask, "Who's that?!" because I know the face but can't remember who they are or what they've done or who they're involved with!  Either that or I'm wondering, "Is this one dead or not?"!  But it's still keeping my attention and I find that if I can't remember who someone is, I try not to fret about it.

I hope they don't drag the series out too long.  I suspect that, like previous similar series, we'll never find out exactly what happened or the reasons for all the returns, but it would be nice if the series is allowed to end before we all get bored with waiting.  Right now it's still gripping and I look forward to each episode.