It’s not long now until season six of Line of Duty returns to our screens.
A high-octane new trailer for the series dropped on Tuesday, featuring guest star Kelly McDonald alongside Martin Compston and Vicky McClure, as their characters face down a suitable cocktail of murder, corruption and seasons-long intrigue.
But it turns out there was more to the 60-second trailer than meets the eye.
Observant fans have discovered an incredibly well-hidden trail of Easter eggs that reveals additional clues about what may be in store for AC-12.
In the first few seconds of the trailer, the shot focuses on a magazine cover, which features a QR code.
Those who scan the code with their smartphones are taken to a PDF file showing a letter “from the office of the Chief Constable”, sent to DCC Andrea Wise.
“I think it is high time we had a much closer look at AC-12,” the letter reads.
“I’m beginning to question whether this department is fit for purpose especially under its current – and let’s be frank – extremely difficult leadership.
“Ted Hastings doesn’t lead investigations, more commit to a crusade. He is oblivious to the politics of the situation which creates problems for me and problems for you because policing is politics.
“And should AC-12 even be led by someone who himself has been accused of corruption?
“The question is what to do next? Is it time for a leadership change? What role should Ted Hastings have in this organisation – if any at all?”
The word “next” in the letter is also hyperlinked – taking fans to a prescription for benzos and opiates written for DS Steve Arnott (Compston).
Within the prescription, fans spotted a hidden morse code inscription, which took them to this video.
The short clip shows a police press conference at which the Police and Crime Commissioner announces that “Operation Pear Tree has completed a thorough investigation into institutionalised complicity between organised criminals and corrupt police officers” – and that no corruption had been found.
There are a further two clues within the video – notably a link to a location on Google Maps in Birmingham, and another mysterious-looking code: “(Hx6) + ? .xyz.”
While we won’t spoil the rest of the surprise, this Twitter user has detailed the cryptic Easter egg hunt through until its conclusion.