I've read a recent interview with Crook, I think it was in the Radio Times, but he stated that this is the last series and will put a lot of things to bed and tie stuff up. It's going to be great!
"They reminded me of... what do you call them? .....Simon and Garfunkle? ..... aholes!"
I speak as one who at last got to do the Gold Dance myself. And we have a nemesis antagonist pair like Simon and Garfunkel - we call ours Mac and Cheese.