At this point in the story, I don't believe enough information has been provided for anyone to be able to make a solid guess as to who Tom Keen really is, or who he really works for. Of course, the same could be said for several other characters but those are all separate posts in and of themselves.

Regarding Tom Keen though, here are some facts that you may or may not have picked up on already (mixed with some questions, theories, etc):

One of my favorite things about this TV series has been how it has masterfully compiled and used its resources (actors/actresses, character development, overall feel of the show, story development, etc.) That said, one of my favorite parts of the show has been its soundtrack. I think they have done a great job selecting music for the different episodes and parts of the show. So, I thought I would share a site that I found that has all of the songs used in each episode with the artist so you can listen to/buy them if you want.

It's seemed to me, especially in the last episode that Tom has become very suspicious, if not aware of Liz's new found knowledge of him. Also I noticed in the Ivan episode (at the end when Liz was finding the pictures), that Tom was kind of looking at her like he knew what she was looking at. Take a look at the ending scene from that episode, it will make more sense. Also if anyone has any idea what Berlin is, please also comment on that?

Throughout the latest episode, and the season more or less, its seemed like Keen and Ressler have had a bit of a romance. I don't know why but it seems like they've been getting closer and closer throughout the show and now that Audrey and Tom are sort of out of the picture for them, in a romantic way, it seems like the shoe would fit pretty well. So will Ressler and Keen end up together?

OK so in one of my more attentive moments, I noticed that at the end of The BlackList episode 15 -- The Judge -- the guy in the cowboy hat ("The Cowboy") tells Reddington that Lucy Brooks, aka Jolene, had been busy. While The Cowboy was telling this to Red, he showed him the contents of what was on Lucy's flash drive which revealed candid images that she had apparently taken (or at least, that she had gotten a hold of).