When Emily Furness (Rachel Shenton) entered Laura Conroy's life in Channel 5 thriller For Her Sins, the pair instantly became firm friends, bonding over their parenting struggles and the hurdles in their respective relationships. But it quickly became clear that Emily was not who she claimed to be.
She had targeted Laura (Jo Joyner) and exploited her vulnerabilities to worm her way into the lawyer's life, but for what reason? And what was her endgame?
As the series rattled towards its conclusion, their "shared secret", which was unbeknown to Laura, was revealed.
For Her Sins ending explained
In the latter stages of the thriller, we learned that Laura's real name was Catherine. Her mother and boss at the law firm, who had changed her own name from Maggie to Ruth, also moved them to a new location when she was a child.
She took the drastic decision after a summer holiday that ended in tragedy.
While visiting Brae Point Cove, young Catherine had made friends with a girl called Millie, who was eventually revealed to be Emily. One day, they decided that they would head out onto the water in a rowing boat they'd stumbled across. But Millie's brother Jamie, who had tagged along, had a tantrum and threatened to tell their parents.
Fearing what her mother would say, Catherine pushed Jamie in a moment of madness and he tumbled into the water. He tried to stay afloat but quickly sunk beneath the surface as the girls looked on in horror. Catherine attempted to save him but despite her best efforts, she was unable to.
Following the ordeal, Ruth ordered Catherine to deny that she was there that fateful day. As a result, Millie was blamed for her brother's death, with the public and even her own parents pointing the finger at her.
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"No one wanted to be friends with me," she told Catherine, recounting a childhood devoid of love or laughter after Jamie had drowned. "They said I was mad. How can anyone ever love me?"
Speaking about her character, Shenton said: "What I liked about Emily is I understood her even if I didn't agree with her. There is sort of a traumatised five-year-old running her life. She's always felt this massive sense of responsibility and in a way needed that justice and explanations, and she takes it to the extreme to get it.
"When I read some of the scripts I was like, 'Oh, don’t do that!' But it always came from a place of there is a bigger objective and I get it."
Eventually, Millie found herself behind bars for her many misdemeanours, which included attempting to kill Laura and her husband Tom, and abducting their daughter Eliza. But that didn't deter Catherine from paying her a visit.
The pair shared a strange conversation in which we gained an insight into the friends they could have been if Jamie hadn't died, and the guilt that Catherine will always carry.
"It's not over," said Millie. "Doesn't matter where you go or who you pretend to be, I'll still be there 'cos I made you feel alive. I set you free. Who's going to do that now?"
She's the one serving time, but Millie still retains the power in their dynamic.
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