Series 10 Rumours & Speculation

[Forever Secret]

I can't see Tom and Zoe returning at all, although I would like to see them come back even for a cameo, however,if they came back they'd be putting their own lives in danger (Which isn't a bright idea as they are no longer part of MI5)
Whatever this secret fom Harry's past is, if anyone from his past becomes involved it'll most likely be someone we've never seen before,
I can however imagine this 'secret' being so bad that it causes Harry to just give up and not fight the enquiry at all, forcing him out of MI5, and like in S9 where Ruth convinced him not to resign, she could convince him also to fight this enquiry, she seems to be the only person he'll really listen to

I wonder if his past would cause the rest of his team to doubt him as well, and what could he have done that's so bad that causes anyone to doubt him? *Waits for S10*