Zoe Slater (Michelle Ryan) thrilled fans with her recent return to EastEnders, though it quickly became clear that she was in some serious trouble.

The iconic character was adamant that she didn’t want to see mum Kat Slater (Jessie Wallace), and was so desperate to avoid her that she climbed out of a window.

When she later called Stacey Slater (Lacey Turner) to explain that it had been a mistake to get back in touch, she revealed that she had done something ‘so bad’ they would never forgive her.

What has she done?

Zoe has got herself into trouble plenty of times before, from ill-advised affairs with her mum’s boyfriends to being framed for the murder of Den Watts.

However, could another dark secret from her past be linked to her current predicament?

Viewers will know that Zoe spent most of her childhood and teenage years believing that Kat was her sister, when in fact she was her mother.

It transpired that Kat had been abused by her uncle and fallen pregnant, with her parents deciding to bring up Zoe as their own.

However, many years later it was revealed to Kat that she had actually given birth to twins, with the second child having been given away.

In a controversial spin-off series, Kat and partner Alfie Moon’s (Shane Richie) search for her missing son took them to a mysterious village in Ireland called Redwater.

Amid much mystery and deception, Kat learnt that local vicar Dermott Dolan was her biological son.

To complicate matters, he was revealed to be a killer, and was later involved in the horrifying boating accident that left Kat fighting for her life.