Line of Duty favourite Steve Arnott has been there from the very beginning of the BBC series - but could he have been on the wrong side of the law the entire time?
The officer, played by actor Martin Compston, is one of the good ones - or so we've been led to believe. Viewers adore him, and whenever he's come close to harm or at risk of trouble at work, there's been a risk of outrage amongst fans.
As the series six finale looms ever closer, there's concern the latest series could be the last - and that Steve might not make it.
But another shocking theory we don't even want to comprehend is that Steve isn't one of the good guys after all, and might even be the infamous and unknown fourth member of 'H' - or at least linked to them.
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