The letter, from Chief Inspector Philip Osborne (Owen Teale) addresses whether Ted Hastings is the best department leader.
It said: “Ted Hastings does not lead investigations, more commit to a crusade. He is oblivious to the politics of the situation which creates problems for me and problems for you because policing is politics.
“And should AC-12 even be led by someone who himself has been accused of corruption? The question is what to do next. Is it time for a leadership change?”
With this in mind, viewers may see Hastings stepping down from his role in the upcoming season.
The gang is still no closer to identifying ‘H’, but fingers are starting to point to McClure’s character, Kate Fleming.