The penultimate episode of Line of Duty series 6 featured a record-breaking AC-12 interview - and fans are sure it's pointed them in the direction of the mysterious H.
The tense 29-minute scene saw Acting Detective Superintendent Jo Davidson quizzed over the killing of Ryan Pilkington after last week's cliffhanger ending, which saw the bent cop and Detective Inspector Kate Flemming pointing guns at each other and then the sound of gunshots being fired as the credits rolled.
In the latest instalment of the Jed Mercurio BBC One drama it was discovered that Pilkington had been killed and Jo, played by Kelly Macdonald, admitted during the long AC-12 grilling that she had fired the fatal shot.
Jo had been controlled by Pilkington via an Organised Crime Gang, which relied on corrupt officers to help them carry out their dirty work. But the identity of one of four bent high-ranking officers - known as H - remains a mystery.
However, the finger appears to be pointing at steely Patricia Carmichael, brought in to take over from outgoing AC-12 boss Ted Hastings.
Every time Hastings (Adrian Dunbar) tried to steer the line of questioning towards the identity of H, Carmichael, played by Anna Maxwell Martin, would immediately shoot him down, looking increasingly guilty herself.
"This force has detected no evidence of institutionalised corruption," she barked as Hastings pressed Jo for answers.
And when Hastings labelled it as a "clandestine network" at work she didn't look best pleased, telling him it was a "hypothetical network".
"We are here to examine DCI Davidson's offending, no one else's," she added.
Fans took to Twitter to say they are now convinced the police chief's a bent cop, with one saying: "DSI Patricia is almost as chilling as Ryan Pilkington."
And another said: "If she isn't H I will eat my hat."
More reaction to Carmichael's actions during the interview:
The tense episode also confirmed that while Jo was indeed related to the murdered organised crime gang leader and paedophile Tommy Hunter, he had been both her father AND her uncle.
For he had raped her mother, Samantha, when she was just 15 which resulted in the birth of Jo. You can read more on that here.
The final episode of Line of Duty is on BBC One on Sunday, May 2
