Coronation Street is to air a heartbreaking stand-alone episode as Carla Connor's psychosis deepens.
The single episode is a part of a dramatic week from the ITV soap which will see the culprit of the Underworld factory roof collapse revealed.
Corrie fans were left in shock in March as Rana Habeeb was revealed as the victim of the roof collapse as actress Bhavna Limbachia bowed out of the soap after three years.
And it has been factory boss Carla who has been left tortured by the death of her half-sisters fiancé with the finger of blame being pointed in her direction.
Convinced that Rana is still alive, Carla, played by Alison King, was seen going on the run as she suffered a mental breakdown but she finally returned home last week, appearing at confidant Roy Cropper's flat.
But next week, the troubled Weatherfield resident will suffer a severe psychotic episode.
The heartbreaking scenes will see Carla ending up on the Victoria street fire escape, believing she is talking to Rana, Hayley Cropper and Aidan Connor.
Show bosses say that elements of the episode will be shown from Carla's point of view as her paranoia and desperation reaches new levels.
Alison, who has so far been praised for her portrayal, has said the scenes are "emotional and "weird" to film but working with real sufferers was key.
"It was really weird trying to encapsulate what she is going through," the 46-year-old actress said.
"I met a beautiful lady through MIND, she came to meet with me at the studios.
"When I talked to her I asked so many questions, she suffers from what Carla is suffering and she told me that during those moments of extreme psychosis you are never not yourself but you are just the most terrified version of yourself."
Speaking about the episode itself, Alison says that Carla is convinced that her family as turned on her and that past friends and relatives have come back to her.
Alison said: "She is busy trying to get the microchip out of her ear she thinks they have implanted.
"It was very hard to play as it was so terrifying for her at that stage – inside her head everything is terrifying.
"She thinks she is seeing Hayley, then she thinks she is seeing Rana and doesn't know if Rana is dead or alive. Then she thinks she sees Aidan.
"To her it is real. She is in a very dangerous predicament and unrecognisable to Peter, [Barlow] who is desperate to rescue her."
But can her reacquainted love with Peter, who is now suffering his own relapse, help her? Or will learning the roof was sabotaged - and who did it - finally relive her of her guilt?
Guess we'll have to tune it a 9pm from Monday, May 27, on ITV to find out.
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