EastEnders' resident teenage psycho Steven Beale stoops to a new low when he attempts to murder his nana Pat by smothering her to death.
Next week, viewers will finally discover that Steven, played by 19-year-old Aaron Sidwell, has been hiding his sister Lucy (Melissa Suffield) from their family in a remote caravan - and it's his gran, Pat (Pam St Clement) who unearths his deceit.
Following her shocking discovery, Pat is accidentally run over by Roxy Mitchell (Rita Simons) and finds herself laid up with a broken leg. When Steven visits her in hospital, he draws the cubicle curtains and smothers her with a pillow in an attempt to silence her from revealing his secret.
An EastEnders source told DS: "Steven hits rock bottom when Pat finds out that he's been hiding Lucy for all these weeks while his family have been frantically searching for her.
"He desperately wants Ian all to himself, but when Pat realises that Steven knows where Lucy is, he takes drastic steps to prevent his beloved nan from revealing all to Ian."
They added: "He goes from confused to psycho in a matter of minutes, grabbing a pillow and pushing it onto her face."
Sidwell was axed from the soap in February when it was also revealed he would become embroiled in a bisexual storyline involving his step-uncle, Christian Clarke (John Partridge). Over the weekend, he openly backed the decision to drop his character.