Line of Duty fans already knew that Acting Chief Superintendent Jo Davidson was related to murdered organised crime gang leader and paedophile Tommy Hunter.
But tonight's penultimate episode revealed that they were, in fact, related twice over.
For not only was Tommy the brother of Jo's mother Samantha, he was also Jo's father. And Jo's birth was the result of rape.
During a record-breaking AC-12 interview scene when Jo was questioned over the shooting of rookie bent cop Ryan Pilkington, DI Steve Arnott told Jo that a DNA analysis showed that Tommy was both her uncle and father.
A visibly shocked Jo replied: "No, No. He was my uncle. That's not true."
She then shared details about her mother, who had committed suicide in 1996 when Jo was a teenager.
"She was born into it - same as me. Hated what her family stood for," said Jo.
"Her brother Tommy what a piece of work he was. He controlled mum's life.
"My mum was still a girl, 15. Raped she told me although I never knew the details. She was forced to go through with the pregnancy. Tommy sent her back to Glasgow. I had no idea about this until Tommy came looking. I had just turned 16."
Jo revealed he wanted her for the police "to do his bidding and be under his control".
Tommy had kept the fact he was her real father hidden from her.
Fans were quick to react to the news.
The interview scene has also now convinced fans that Patricia Carmichael is H. Read more about it here.
