[Spoilers] BBC Press release - series 9

[Maike]

RA said in an interview: "Nightingale comes through as a thread with the old home secretary that was in the last series. That thread is still alive, but it does come to an end at that point and then we have a new problem."

That makes me think that the series 8 storyline will be wrapped up in the first episode/aftermath of Ros's death and that the old HS might have been involved into nightingale after all. He claimed that he has been set up, but what if he hasn't?