Line of Duty viewers were shocked when, in Sunday night's episode, DS Kate Fleming appeared to betray her old AC-12 pals to her new bosses at MIT (murder investigation team), by warning them that AC-12 planned to launch an investigation into Operation Pear Tree.
MORE: Line of Duty's many acronyms, debunked
Although fans were disappointed in Kate, many pointed out that she could very well be tricking her new colleagues into trusting her - a theory that appeared to be confirmed when some eagle-eyed viewers spotted her looking at a very interesting profile on her computer!
WATCH: Line Of Duty season six episode two: the net tightens
In a blink-and-you'll-miss-it moment, Kate can be seen looking at Ryan's profile, proving that she does indeed know that he is a member of the OCG who has joined the police force, despite pretending that she doesn't know who he is.
Is Kate playing the long game?
Tweeting about the moment, one person wrote: "Recognise someone Kate? She has to be undercover for AC-12 SURELY." Another added: "I missed this at the time but look what Kate was looking at when AC-12 came in #LineOfDuty #LineofDuty6."
MORE: Line of Duty star talks leaving show before season six
MORE: Martin Compston did soup diet to fit back into Line of Duty suits
Has Kate truly betrayed Steve?
Without having spotted this clue, other viewers were also certain that Kate hadn't really double-crossed AC-12. One person wrote: "Me explaining to my friends who have never watched LOD that kate has not left AC-12," while another tweeted: "Could Kate be double-crossing AC12 to double-cross MIT #LineOfDuty."
Have you been enjoying the series so far? Check out our breakdown of episode two here!
Like this story? Sign up to our newsletter to get other stories like this delivered straight to your inbox.
