EastEnders fans got one more twist last night after it was revealed Lucy Beale's murderer, her half-brother Bobby, does not know he killed her.
Viewers watching the live episode saw Jane Beale, played by Laurie Brett, explain how she told him Lucy survived their fight and left the house before being killed by someone else.
Show boss Dominic Treadwell-Collins said: "He thinks she got up and walked out the door, and that is what Jane has said to him."
The producer said he initially had two other suspects in mind for the murder before deciding to put Bobby in the frame and added the idea had been partly inspired by the murder mystery novels of Agatha Christie.
He said: "Three of Agatha Christie's best ones - one of them the detective did it, one of them everyone did it and one of them the narrator of the story did it. We always wanted those big twists."
He said it was a conscious decision not to show the fight between the two characters to protect the young actor, Eliot Carrington, who plays Bobby.
Treadwell-Collins said: "The fact Bobby didn't deliberately do it and it was an accident is very, very important. I wouldn't lumber a child with that."
More than 10 million people tuned in to each of the two episodes which finally revealed Lucy's killer and the shock return of Gillian Taylforth's character Kathy Beale.
Taylforth's return was so secret that even her own children did not know - meaning they missed the moment she stepped back on screen.
Treadwell-Collins said her on-screen son, Adam Woodyatt, was so shocked by the news that he burst into tears.
She said: "It's been awful and the only person that knew was my other half Dave. I was trying to say to the children the other day, 'try and watch EastEnders on Thursday', I said to them, 'because it's live and Adam is going to do something really silly so everybody starts laughing' and I thought that will get them watching so they can see it then and go 'ohh', but my daughter said 'I'm working until nine mum' and my son said 'I'm playing football over the rec', so I went 'oh fine, thanks very much'."