A Line of Duty fan has been told she should be on the team after spotting a huge clue to the plot on a computer screen behind Vicky McClure's character DI Kate Fleming.
During the episode, Kate ridiculed DI Steve Arnott played by Scot Martin Compston and upset viewers after appearing to grass on her old AC-12 units.
Steve had given Kate a heads up about the raid at her new boss DCI Joanne Davidson's office but she ended up informing Joanne which stopped the raid and delayed action.
During the episode, Kate recognised a young officer, Ryan Pilkington, who first appeared in the show as a young kid working for Tommy Hunter, and delivering burner phones.
He later returned in his twenties working for undercover cop John Corbett and slitting his throat at the end of series five.
This time round, he was reappeared at the Central Police force as a student police officer, making a seemingly innocent cup of tea for DCI Davidson.
Kate was sure she recognised his face asking him if they'd worked together before - which he denied.
However, eagle eyed viewer Toni Williams who happens to be a criminology and psychology student, noted that Kate appears to know who he is already, after spotting his picture and profile on her computer screen in the background of the shot.
Toni tweeted: "Kate knows!! #LineOfDuty did anyone else clock this??"
Fans couldn't believe Toni's spot, thinking that it had been edited. One commented: "What a spot. Thought you'd edited it, but been back and watched it again. Kudos."
Someone else added: "You could spot an armed robbery down a side street from a speeding police car."
Another said: "You're AC12 you are. Going to be looking out for your tweets every week now."
And one other suggested: "Eyes like a hawk. You should be investigating bent coppers."
