Coronation Street's Claire Sweeney worried for Cassie's future amid Ken poisoning

With Cassie firmly the guilty party, will her moment of madness be found out?

Sweeney has opened up on the scenes to press including RadioTimes.com, explaining how she would be "fuming" if she was a fan at home watching someone attack dear Ken!

What did you think when you heard that Cassie was going to poison Ken Barlow?

Claire Sweeney: "I was shocked. It’s Ken Barlow, he’s a national treasure. I’m going to be Public Enemy No. 1! I think viewers are going to hate her.

"The funny thing is that they’ve just started to like her – they were finally warming to her – and then this happens. In my head, playing her, I’m trying to find saving graces, but I don’t know if there will be any. I’m a Corrie fan and I’d be fuming watching this.

"Already in the summer, when I went on holiday to Majorca, all the old dears were saying to me, 'You leave Ken alone. Don’t you be upsetting Ken now.' And that was before I’d done anything!"

How did you find out about the storyline?

CS: "I was talking to the producer and it was casually mentioned to me and then the conversation carried on. I went: 'What? Did I hear that right?' I was shocked, and then I thought: 'What fun!' She’s certainly not boring. I’m not just asking for a hotpot in the Rovers. It’s exciting, and working with Bill Roache (Ken Barlow) is an absolute dream; I love it."

Why does Cassie initially put painkillers and blood thinners in Ken's tea?

CS: "She doesn’t want to hurt him – she just wants him to need her. She adores Ken. The two of them find these moments of absolute affection with each other. They love being with each other.

"So, when Ken says he can’t afford to keep her on, she’s devastated – where’s she going to go, what’s she going to do, who is she going to be with? There’s an anger and a hurt and a feeling of abandonment. It’s not even necessarily money-orientated, she likes the life she’s got looking after him. There’s an element of Munchausen’s to it."

When Ken then feels unwell, he tells Cassie he'll pay her an extra pound an hour if she accepts her job back. How does she feel?

CS: "It’s win-win in every way, and she goes and gets her nails done. She is back where she wants to be."

How does Tracy react to Cassie's continuing presence in her dad’s life?

CS: "She orders Cassie to sling her hook and stop sponging off Ken, and says that she will look after him. Tracy is very territorial with Ken. She doesn’t like having another woman in the house, and especially another strong woman, who’s not frightened of her. Kate Ford and I are having a great time because we’ve had some great slanging matches, which has been brilliant."

What is Cassie's relationship with Steve McDonald like now?

CS: "They spent the night together, but at this point that was just a one-off. Nothing has really happened since then. They had a fall out, because he accused her of sponging off Ken. It cooled off a little bit between them.

"I think at the moment he’s torn, because he still fancies her and he still likes being with her, but he’s trying to play devil’s advocate and sit on the fence. He’s listening to what people are saying about Cassie, but he also likes having her around the house – he enjoys her company and there’s a spark. I think there’s unfinished business."

Does Cassie feel bad when Ken falls ill and is taken to hospital?

CS: "She feels terrible. There’s absolute remorse – she never wanted to hurt him and she thinks she’s gone too far. She’s not trying to harm him; she just wants him to need her. I think she regrets giving him blood thinners. There is an element of guilt – she does question herself."

Does Cassie continue to drug Ken?

CS: "She googles drugs that make you drowsy and comes across antihistamines. She’s realised the consequences of the painkillers and the blood thinners and that they were a bit dangerous, so she switches to antihistamines, because she believes they are not as harmful and they’re harder to detect.

"I think Cassie will go to any lengths to keep this going. She’s not poisoning him with the intention to harm him, it’s just to keep him a little bit dopey, so he keeps her on, so he needs her."

Does she feel at all guilty about what she is doing?

CS: "Everything has been done with survival in mind. She was on the game; she was abused when she was younger – so everything is about survival, and I think this is about survival as well. But she’s conflicted, because I’m not sure she’s had genuine feelings for anyone before, and she has with Ken. He’s kind to her and he’s forgiving and he has her back as well. She is a little bit ruthless, but then there are moments where her conscience is pricked, because she likes Ken."

Can you describe their relationship?

CS: "It’s almost like a Professor Higgins situation, and she wants to keep it. She adores Ken. He teaches her about things she never knew about – classical music, Portuguese music, language, foods, wines. She’s suddenly introduced into this new life with him and she doesn’t want to lose it. She loves being with him, and she loves the job and having money and she adores her new lifestyle as well – suddenly she’s got new hair and she’s getting her nails done."

Is it just about money and the perks of the job?

CS: "It’s not black and white – it’s to do with feelings of abandonment; she doesn’t want to lose the security she’s suddenly got with Ken. A lot of people look down on her, but with Ken she feels like she’s been properly seen for the first time. He’s teaching her things; he’s seen that she’s not stupid and he doesn’t think she’s rough – he respects her. There’s genuine fondness and love between her and Ken. There’s a real affection.

"She’s not really had this before – she’s never had anyone who cares for her, she’s never had anyone who respects her, or anyone who wants to teach her anything."

Was Bill Roache taken aback by the storyline?

CS: "We were both a bit shocked, and it sounds awful that I’m poisoning him, but she just wants him to need her. She wants to keep her job and she loves being with him. Bill is like myself, he’s very keen to play the affection between the two characters so it’s not just black and white – there is a grey area."

What's it like working in the Barlow house?

CS: "There are three great relationships there for Cassie within the house. There are the dynamics of Cassie and Steve – they’ve got a chemistry. She absolutely adores and looks up to Ken. And then there’s the cat-fighting with Tracy. My dream has always been to have a scrap on the cobbles with Tracy Barlow, and it could be likely now."

How would Steve and Tracy react if they knew what Cassie was doing?

CS: "I think they would be genuinely horrified, as will the public. The minute you say 'poisoned Ken Barlow', there’s genuine horror!"

Do you worry that this storyline could signal the end of your time on the cobbles?

CS: "It does cross your mind. When I got this job, if you’d have told me that a year and a half later, I’d be here having a big storyline with Bill Roache, I’d have been so grateful for that.

"In my time in Corrie, I’ve had big scenes with Maureen Lipman, a big storyline with Bill Roache, I’ve got to snog Steve McDonald and have a cat fight with Tracy. What more could I want? So, if this does signal the end, I’d go, 'Well, hasn’t that been great? I’ve been blessed.'"

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