It’s official; Kat Moon (Jessie Wallace) finally knows the truth about her missing child, thanks to a visit from Sister Ruth (June Whitfield).
At the moment, all we know is that the nuns named her baby boy Luke, and that he was taken in by a family from Ireland.
So where is he now?
While many EastEnders viewers are 100% convinced that Kat Moon (Jessie Wallace)’s secret son is none other than soap hunk Sean Slater (Robert Kazinsky), a new theory has fallen into place.
And it’s a humdinger.
In February 2014 (a very big year for EastEnders fans), Stacey Slater (Lacey Turner) made her much-anticipated return to the BBC One soap.
But she wasn’t alone. Or, at least, she wasn’t alone at first.
Accompanying her was her very-handsome boyfriend, played by Busted’s Matt Willis.
The name of this boyfriend?
Luke. Luke Riley.
As in, LUKE!!!
Coincidence?
Strangely, for such a big celebrity cameo, Matt Willis was only in the show for a few weeks.
At the time, he said: "I am so thrilled to be a part of such an iconic show.
"I grew up watching EastEnders, so this is really exciting for me."
Executive producer Dominic Treadwell-Collins said: "I've always loved Matt and it will be a real treat for viewers to watch him and Lacey together on screen as part of her return to the square.
"Luke gives as good as he gets, so is a great foil to Stacey. Pity she's been lying to him since the day she met him."
Fans responded well to Matt’s performance, and many called for him to be given a more permanent role in the show.
Could this mean that Luke is coming back very soon… as Kat’s son?
However, despite the fact that this rumour is gaining traction, people are still far more convinced by the Sean Slater theory.
First of all, Kat’s parents wanted to keep her little girl in the family, so it makes sense that they would have done the same with her little boy.
Jean has always been fond of her niece Kat, after all… and she’s always seemed to love Stacey, her confirmed biological daughter, far more than she loved poor old Sean.
Speaking back in 2013, actor Robert Kazinsky did predict that Sean could one day make a comeback to Albert Square.
"My good friend Dominic [Treadwell-Collins] did just take over running it and so I am pretty sure he will ask me to come back at some point.
“At the minute, it is not viable that I could come back for any length of time because I don't live in this country and I don't particularly want to pay tax here.
"I live in America and I have done for five years, but never say never," he commented to the Belfast Telegraph.