I agree with everyone that James Spader makes this show. Without him, I don't know if I would continue to watch. While many have speculated that he is the father of Elizabeth Keen, I don't think so. Especially after seeing last nights episode, the picture he took out of the book of the young woman, I think that was his daughter.
The one thing I really like about this show is that the 'main' story only takes up about a half hour of the whole show. The beginning part and tail part of the episode are devoted to the bigger mystery. It's very refreshing, it's kind of like two shows in one.