Viewers left shocked by The Pact's major twist in episode three

Are you watching the BBC drama?

It's safe to say that Monday's episode of The Pact left viewers stunned. The third episode of the BBC drama, which stars Laura Fraser and Julie Hesmondhalgh, revealed a major twist in the story involving five co-workers all loosely involved in the death of their boss, Jack.

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Warning! Spoilers ahead for episode three...

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WATCH: The Pact on BBC official trailer

The third instalment in the murder mystery saw the gang continue to battle with an unknown blackmailer, who is threatening to expose their dark secret.

Anna (Laura Fraser) was forced to hand over £5,000 to the blackmailer from her savings account, telling her husband (played by Jason Hughes) it was for a friend in financial trouble. However, things got more intense when the scammer demanded another £10,000. At this point, Anna had enough and decided to track the blackmailer's phone.

Eventually, she found herself turning up at a mystery house, only to find her co-worker and friend Nancy (Julie Hesmondhalgh) holding the phone. The major twist was completely unexpected for those watching at home. One person wrote on Twitter: "Whaaaaaat???? NANCY!!!??? #ThePact."

A second person tweeted: "OMG! Well this just got waayyy more interesting #ThePact," as a third said: "Can't believe it was Nancy blackmailing! #ThePact."

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Julie Hesmondhalgh and Laura Fraser in The Pact

Star of the show Laura recently opened up about her role as Anna, admitted it was a "difficult" gig due to the intense storyline and her character's secretive journey. Chatting to HELLO! in an exclusive interview, she said: "She's in so much emotional turmoil and to keep that going really took a toll.

"It's funny because your body doesn't know that it's not real. Your amygdala still fires up and then it's like 'Oh my god something really bad is happening!'

"When you're acting shocked or afraid, all your pathways are doing what they would do if you really were, so there's effects of that. I know it's totally privileged! But it was difficult."

The Pact continues on Tuesday at 9pm on BBC One. 

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