Casualty spoilers follow.
Tonight's (November 26) episode of Casualty will see some upsetting scenes as Stevie Nash is attacked by the controlling boyfriend of a patient she's treating.
Ethan later finds a seriously injured Stevie curled up on the floor and rushes her into resus.
Speaking about the storyline to Inside Soap, actress Elinor Lawless, who plays Stevie, said: "If Stevie sees anybody vulnerable being taken advantage of, which happens with her patient Flo in this episode, she won't have it.
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"With the attacker, Jordan, he's so polished and slick — so I think what happens will shock people. There's an unexpected brutality in the attack, and Stevie doesn't see it coming until it's too late. Steve realises she's bitten off more than she can chew only a second before it happens."
Discussing how Stevie will be affected by the attack, Lawless said: "The hospital for Stevie is her safe place, it's her playground. So what happens leaves her incredibly open, vulnerable, scared and childlike really, which is something Stevie never wants to feel.
"What I will say is that following the attack, things take a real turn and there's a lot more to see between Stevie and Marcus. I think the audience are going to find that quite interesting to watch because their relationship is definitely not what it seems," she added.
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Lawless also admitted that the audience's warmth towards Stevie "ebbs and flows", but said that she actually enjoys that her character isn't so easily likeable.
"Those little oscillations are interesting," she added. "Her humility and honesty can sometimes be endearing, but sometimes infuriating. I enjoy the fact that Stevie's so complicated because it's fun to play."
The actress also praised the cast and crew of the medical drama for creating "such a lovely atmosphere on set" and said that she's loving her time on the show.
Casualty airs on Saturdays on BBC One and streams on BBC iPlayer.