Who is Tom Keen and who does he work for?

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):

• Name (current): Thomas Vincent Keen
• Name (alias): Anton Piere-Louis
• Name (alias): Dieter Neumann
• Name (alias): Lucas Ponald
• Name (alias): David Balthis
• Occupation: Teacher, 4th grade
• Spouse: Elizabeth Scott Keen
• Lover: Gina Zanetakos, aka Shubie Hartwell
• Answers to "Berlin"
• Designation: DS451

It seems possible that the first time Tom Keen met Raymond Reddington (in person) was outside the hospital where Sam -- Lizzie's (adopted) father -- died.

While I don't believe the writers have given us enough information yet to determine who Tom Keen works for, I think it's very possible that he works for a major organization like INTERPOL. Regardless of who he works for, his current mission and "target" appears to be his wife Lizzie. What Lizzie is being targeted for is anyone's guess at this point, but it seems apparent that whatever mission Tom was on started to go south at some point. Almost as if he unintentionally fell in love with Lizzie and now he doesn't know what to do.

At the end of episode 15 -- The Judge -- Tom Keen visited Lucy Brooks's hotel room to tell her that he "can't, because I love my wife." According to Brooks, aka Jolene Parker, that was the "wrong answer", after which Tom suggested that he was being tested by Brooks.

This begs the question, "What was Tom being tested for?" The only thing I can come up with is pretty much what I stated above: Berlin sent Tom, who was one of "many candidates", on a mission where his target was Lizzie. But after a while things started to get real for Tom and at some point he unintentionally fell in love with Lizzie, to the point where the two of them were even in the process of adopting a child. Then, after "going dark" for several months, Berlin started to question whether Tom was still focused on his mission at which point they sent Lucy Brooks to check up on him.

Knowing that Brooks knew the truth -- that Tom's mission went sideways -- he told her to call everything off with Lizzie and then killed her to prevent her knowledge from getting back to Berlin.

I also think it's very possible that Tom actually works for Reddington and if that's the case, and if Tom does in fact work for a major organization like INTERPOL, by default that would imply that Reddington also works for INTERPOL (or whichever agency Tom works for) which is really not that far-fetched in my opinion. Think about it: Reddington himself has stated that he's "asymmetrical" and doesn't need passports, visas, etc, to travel freely on an international level -- something that would theoretically apply to just about any member of INTERPOL (the International Police). He also subtly suggested that he was actually a good guy when he said something about "working my side of the tracks" to Ressler and Cooper and at several other points.

Further, he (Reddington) killed Diane Fowler which is something Cooper started to investigate, only to be stopped by orders of someone "up top"; and at that point, the only people who knew Reddington was the killer were Reddington himself, Mr. Kaplan, presumably Dembe, and now (in theory) the D.C. field office who was instructed to dismiss Cooper from the investigation.

Interesting fact: INTERPOL, originally known as the International Criminal Police Commission, was founded in 1923 and for several years was headquartered in a city called Berlin.

Anyway, that's just one of the many theories I have. Feel free to comment or post your own theory. :)