Ok, so having watched the first three episodes I deduced the following;
Agent Cooper has been possessed by Bob for 25 years and has been responsible for the murder of the woman discovered dead in episode 1 even though another guy has been arrested. The real agent Cooper has been told by Laura Palmer it's time for him to go back.
I always felt that AC was able to solve crimes because of his psychic sensitivity but this also made him vulnerable to be possessed by Bob.
But who is Dougie? The 'manufactured' version?
That black case thing has a link to the red room obviously.
Who was that lady in the spaceship thing who pulled the leaver?