EastEnders' Whitney Dean will vow to bring down serial killer Gray Atkins this Christmas on the BBC soap, when she believes she has found proof that he murdered his wife Chantelle.
Chantelle was killed during a row with her abusive husband Gray last September, with him leaving her to die instead of helping her.
No one knows this, despite Kheerat Panesar being suspicious given he knew Chantelle was planning on leaving her partner the day she died.
Since then, Gray has gone on to murder Tina Carter and even Whitney's boyfriend Kush Kazemi, but this is also yet to be discovered.
In scenes to air later this month on the BBC soap, Whitney vows to bring down Gray after working out he caused Chantelle's death - claiming to have proof.
Fearing his pregnant wife-to-be Chelsea Fox could face the same fate, she faces a race against time to expose the killer before their wedding.
Whitney and Gray were close, but recent scenes have seen his dangerous and dark behaviour exposed and this leads to her becoming his enemy.
She decides to stop the wedding and get to Chelsea before Gray can marry her, but will her plan work?
Whitney comes to the conclusion of Chantelle's demise after clues begin to piece together, leaving her startled.
Confident she has proof, she tells Chelsea everything she knows - but will she listen, or will Gray get away with it?
Whitney actress Shona McGarty has teased all on the moment her character learns the shocking truth, and how Whitney will react.
She said: "Obviously it comes as a huge shock. She would never have thought he was capable of murder.
"Heartbreaking as Whitney and Chantelle were so close. You just can’t imagine it, like one of those horrible documentaries you see where your next door neighbour is a murderer, it’s crazy.
"Freaks her out knowing she was so close to Gray and potentially could’ve had a relationship with him. That is dangerous and scary, and a huge shock."
EastEnders airs Mondays and Fridays at 8pm, and Tuesdays and Thursdays at 7:30pm on BBC One.
