@KittyOSullivanKrauss
New to the thread but delurking to say that I've just rewatched the end of S5. Carmichael dismisses Brandyce so there is a vacancy for a DI in AC3, and she looks impressed with Kate's work. Plus she seems to remain convinced that Hastings is a wrong 'un....
That seems like a good spot!
I think the theory that Kate is undercover for AC-3 makes a lot of sense - Kate’s behaviour is very much like when she has been undercover before, and makes sense of why she’s being off with Steve /thwarting AC-12s plans.
Though...what would be the bigger picture that AC-3 were onto (why would Kate not just fess up to Steve and get them to back of, rather than risk AC-12 scuppering AC-3’s work?)