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It's safe to say it's been one of the most thrilling series so far, as AC-12 have been intently tracking Joanne Davidson (Kelly Macdonald) and her unusual handling in the investigation into Gail Vella's (Andi Osho) murder.
After Joanne lures DI Kate Fleming (Vicky McClure) to a lorry park for her to be assassinated by copper killer Ryan Pilkington (Gregory Piper), it was revealed in Sunday night's episode that Kate had shot Ryan twice in the chest, before fleeing the scene with Joanne.
Others didn't understand why Kate let Jo take the rap for the shooting when it was legal, and were unsure about why she was so reluctant to surrender her firearm when she was apprehended by armed police.
Taking to Reddit, one fan wrote on the Line of Duty thread: "I can't help but feel there's more to Kate's 'post shooting Ryan' escape but I'm not clever enough to work out what it is. The direction, soundtrack and reasoning behind what she's doing seems really weird / deliberate.
"I just can't place my finger on it, anyone any ideas?"
Another fan noted: "Her character has been off the whole season. She is a smart woman yet she decides to ask Steve [Arnott] after going to a dodgy lorry park if there's anything suspicious going on.
"There was around 25 minutes between Kate leaving the bar and calling Steve."
"It was a plan to get Jo to tell the truth to Kate before she was arrested and interviewed by AC 12," suggested one Line of Duty armchair detective.
"Steve and Kate probably believe there is a mole in AC 12, which mean that each other is probably the only people they can trust in AC 12. Especially after what happened to Jimmy Lakewell."
A second viewer theorised: "I think Kate fully believes that Jo is bent through manipulation rather than because she benefits directly. This was her opportunity to try and get Jo to trust her completely and open up.
"In the time they had she managed to get out of Jo that she believed her dad was a bent copper and she was led to Gail Vella's laptop, which is more useful than anything AC12 got out of her."
However, a third fan has suggested the most comprehensive theory, saying that Kate feared that AC-12 had set up the whole lorry park situation - and was left feeling betrayed by her former colleagues.
"The order was to 'get rid of her'. Meaning assassination, but there are other ways, including imprisonment," they explained.
"She's watched Steve and Ted [Hastings] be framed for conspiracy to murder and both of them only escaped life sentences because of her.
The fan continued: "Steve gives the explanation that this was an extreme circumstance because of the disruption to the chain of command.
"Jo gets the order. Osborne puts Carmichael in charge. Carmichael with Osborne's agreement pulls surveillance that puts Kate in danger but also means there are no neutral witnesses to the incident- immediately post shooting she can't exactly trust that Jo would back her up that it was self defence.
"If you go back to the conversation outside Steve's apartment, she didn't believe that Jo wasn't aware of and had nothing to do with the surveillance being pulled, despite Jo's pleading, until Jo puts her fingerprints on the gun. She also runs to get valuable information out of Jo.
"The burners and the garage are sensible contingencies I would bet Steve and Kate put in place either after S3 or S5. AC12 is a dangerous workplace! People keep getting framed and blackmailed! She only thinks Steve could be in on it at the very end because without knowing about the trackers it's the only possible explanation for why they were intercepted in his car so quickly."
Hmmm...it's sort of convincing?
Other fans have suggested that Kate could actually be H, which is why her behaviour seemed so erratic last week. You can read more about that theory here.
There's only one way to find out just what on Earth is going on, and that's by watching Line of Duty on Sunday at 9pm on BBC One.
Featured Image Credit: BBC
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