Vinay had been looking into some wrongful arrest claims from the strike, one being Gary's, which is when the subject of 'spycops' was raised with Ian St Clair and Kevin Salisbury.
Before he was murdered by Scott Rowley, Gary had been carrying out his own investigation into the identity of the informant who had infiltrated the community and caused irreparable damage, before choosing to stay while their colleagues returned to the capital.
What possessed them to relinquish their old life and assume their alias permanently? Were they ordered to do so as part of an extended operation? Or was it for personal reasons?
After learning that Ian's wife Helen had a restricted police file, which Ian himself wasn't even aware of, Kevin believed that he'd unmasked the double agent. But during a meeting at a local hotel, Helen vehemently denied that allegation.
Helen and her mother had been living in witness protection because of the threat posed by her father.
"He had this horrible habit of trying to kill us," she told Kevin.
And the reason Helen chose not to tell her husband about her past?
"Because as soon as you tell just one other person, even the person you love most in the world, it starts to define you and shape you, and I refuse to give him that power," she explained.
The narrative then jumped back to the '80s where we discovered what happened that fateful night during the harvest festival, which all miners, regardless of allegiance, were invited to attend, and, in turn, we discover the identity of Keats.
On the night of the gathering, Kevin had been ordered to remain on guard at the local coach depot, where the police were storing their equipment. But he foolishly chose to abandon his post to meet Jenny Harris at the allotment.
Ian and Martin's dad Ron, Jenny's dad Jonathan and Warnock, among others, knew that Kevin wouldn't be there and took the opportunity to break into the storehouse. Gary, however, thought it was too risky, told them as much, and chose to spend his evening at the allotment, where he ran into Kevin and Jenny.
The raid, which was supposed to be a quick in-and-out job designed to rub the MET's nose in it, and nothing more, escalated into a full-blown disaster.
A fire broke out, killing Jenny's dad, with Martin narrowly avoiding death himself after running into the burning property to rescue his father.
It was Keats who had informed the men that Kevin wouldn't be on duty as instructed. She was posing as a local barmaid and the daughter of a miner who had been moved down to Clipstone from Bury.
It was that night which forced Keats to reevaluate what she had been instructed to do in the village.
"Why? Why am I here?" she said on the phone to a colleague back in London. "I don't know anymore. F**ck."
After the officer reassured her that she was carrying out vital work, she supplied him with a number of names, including Gary's, which resulted in his arrest, despite no involvement in the storming of the depot.
Ron St Clair was also arrested after Ian confirmed that his father was involved. But in an attempt to assuage some of his guilt, he informed Gary that there was a "source" in the village who had been suppling information to the authorities, which kickstarted his decades-long mission to unmask the spy.
In the cold light of day, Keats's conscience refused to let up and during a conversation with a young Bill Raggett, she shared her growing concern.
"We're just kids out here playing games, no clue what," she said. "Stirring sh*t up, starting fires. Who's the enemy? Is it this lot? They've done nothing to me but welcome me in. Why did I give those names? I shouldn't have."
It's then that we learned who Keats was: none other than Daphne Sparrow, the matriarch of the local crime family.
Like Bill, she had assumed the identity of a child who had died to ensure that there was no risk of any major news stories being traced back to her.
In the episode's final moments, we watched as Daphne and Mickey, who had already grown close, grow even closer. Initially, she refused his advances, claiming that her life was too "complicated" to factor him in, but he encouraged her to follow her heart and eventually, she surrendered to romance and a brand new life.
But the cover she has managed to protect for almost 40 years looks set to crumble now that Scott appears to have discovered the truth. Will Daphne's true identity be exposed? And is she set to go the same way as Gary?
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