Yikes. I've gotta say - I did not see that one coming. I'm really not sure how to process everything that I just witnessed. I admire this show for not resting on its laurels, and giving us something truly different to contemplate. I have no idea how we're supposed to go forward from here. Let's start with some of my complaints.
Cons:
The mystery itself is sort of... incidental. It turns out that there's a secret memo that's connected with Bracken's criminal activity. Because of this memo, Beckett's old team at the FBI ends up dead, and Beckett finds out that she might be next. The guy she runs off with tells her that anybody that she contacts will be in danger, so Beckett has to go off the grid. They end up meeting Castle's mother-in-law Rita, a bad ass spy lady who's married to Castle's wayward father. We watch as Castle, with Alexis and Hayley assisting, puts together the pieces of the puzzle at the same time that Beckett and Vikram do the same. In the end, Bracken ends up dead in his prison cell, and the Attorney General is revealed to be connected in some way. It all turns out... sort of unfinished. The details are hazy, and we're left uncertain as to the truth.
Honestly, the reason this is a con is because it doesn't matter. I honestly could not care less about the specifics behind this mystery. It's just not compelling to rehash old material like this. I also thought the introduction of Rita came right out of left field. It was almost like they wanted to bring Castle's father back in, but they had to settle for an awkward replacement. Why include her at all? I mean, I guess it was cute to see Beckett welcomed to Castle's family by another mother figure, but otherwise it was totally out of place.