*This article contains spoilers for tonight's (Monday, July 8) episode of EastEnders on BBC iPlayer and is yet to air on TV*
EastEnders airs a shocking KILLER confession in tonight's episode - and it's Billy Mitchell who's left reeling at the news about his mum.
It's Stevie Mitchell's birthday today and Will wants to make it a special day for his new-found grandad.
Billy, who's keen to bring his whole family together, agrees. So he sends Will off to get a cake and balloons and plans a party in The Vic.
But when Billy's new nephew Harry is a bit sneery at what he's planned, he starts to reminisce about the good times he had with his parents in Southend.
The trips were to celebrate Stevie's birthday each year, which also happened to be the birthday of Billy's mum - Val. He explains they met when they were both out having birthday drinks.
And he tells half-brother Teddy about how he and his brother Charlie ate so much seaside treats they were sick!
There's a spectre at this feast, though, in the shape of Phil Mitchell who is NOT happy about Stevie showing up in Walford and has got Ritchie on the case trying to dig up some dirt on the old man.
Phil softens - just a bit - when Billy points out that he was always fond of his mum, and that the party is for her too - wherever she is.
But when he's alone he takes a call from Ritchie that leaves him shocked. And it's clear it's something big, when he heads over to the pub.
As Billy toasts his new family and his mum and dad, Phil draws Stevie to one side and tells him he needs a word.
And soon Billy joins them at Phil's, with annoyed Mr Mitchell telling his uncle and cousin that Stevie's got something to say.
Stevie shows Billy a birthday card he bought earlier, which he's written to Val - Billy's mum.
Surprised, Billy asks his dad if this means he knows where his mother is.
Stevie admits he does - and that he's always known.
And then he drops the SHOCKING revelation that Val is dead!
While Billy struggles to take in the news, Stevie adds to his torment by saying she died not long after she left the family - back when Billy was just nine years old. He says he didn't want to upset Billy and couldn't tell him back then. But Billy demands more information.
And eventually, a reluctant Stevie tells Billy exactly why he couldn't tell his sons that their mum had died.
"Because it was all down to me," he admits. "It was my fault."
What?!
Does this mean Stevie killed his first wife? And how will Billy cope with the news?
EastEnders airs tonight at 7:30pm on BBC Two. Check our TV Guide for more information.
