started as nicholson's deputy in the counterterrorism center. at that time radical islamic terrorism was on the rise. so there was a lot of real work stuff going on that you had to focus on. >> they were looking at critical players who eventually became known post 9/11. >> in the middle of all that you're trying to catch your boss compiling information he's going to give to the russians. >> to have a human source in touch with him every day is invaluable. >> getting to know him was part of the exercise. i spent a lot of time going to lunch with him, drinking beer with him. my goal with the investigation was to immerse myself in him but it was mentally draining every day. because i describe him as a flawed personality, a flawed man. over time that became very parent that he had a special view of himself.