As most fans know by now, next week's episodes see Alfie finally discover the full story behind Kat's affair as he resorts to desperate measures to get the answers he craves.
When Alfie secretly follows Kat (Jessie Wallace) to a bedsit on George Street and demands an explanation for her latest deceit, the truth dramatically unfolds and his heart is ripped apart…
Digital Spy recently caught up with Shane Richie, who plays Alfie, to hear his thoughts on the big reveal and what fans can expect from the aftermath.
Are you excited about the truth finally coming out next week?
"Most definitely! We filmed the episode two months ago, so we've been sitting on this for a long time now. Kat and Alfie went off screen for a little while, but the storyline kicked in again last week when Alfie started becoming suspicious. The viewers will see that culminate next week when Alfie finally discovers who's been sleeping with his wife.
"Playing all of that has been brilliant, especially working with Jessie on those dramatic scenes. I think we do angst very well!"
What kind of a reaction are you expecting from fans when they finally find out the truth about Kat's lover?
"It's so tricky to answer that question without giving away the outcome! But right up to the reveal, Alfie believes that it's a certain one of the Branning brothers. Even just before the 'doof doof' at the end of the episode, the viewers will think that it's the person who Alfie believes it is. It's only in the last ten seconds that you realise who it actually is. So I think the reveal is going to be very interesting."
It sounds like we see a different side to Alfie, with some really angry scenes in the reveal episodes. Did you enjoy that opportunity?
"Definitely - I enjoyed giving Alfie some balls. You've got to remember that the character has been in prison in the past. He's always worn his heart on his sleeve and seen the good in people, and this is the one time where he says, 'Enough is enough - no more Mr Nice Guy'.
"Even though he's angry, you'll still see Alfie's pain when his whole life just crumbles in his hands. He's holding on for dear life, and I think there's something really endearing about a bloke who's trying to keep his family together. Alfie wants to keep the family unit strong, but there comes a point where there's only so much one person can take. That's enjoyable for me, because it's an emotion that I've not really played with Alfie before."
How much can you tell us about the aftermath of the reveal?
"I'll be interested to see the audience's reaction to what happens afterwards. You'll see that Alfie really wants to move on from Kat quickly. He goes into denial and he puts his head in the sand.
"A relationship with Roxy forms, and I think the audience have wanted that for a long time. But it's how that relationship forms and the basis of it which becomes really interesting - it starts to cause some problems in the Square.
"We're still filming the aftermath now and there's a bit of a triangle going on now with Kat, Alfie and Roxy. I think people want to see Kat and Alfie together, but at the same time, it feels like they can never be happy. So how can these two people be together and be happy? That's what I think will play out next year, if they do end up getting back together at all."
Are you still filming lots of scenes with Jessie at the moment even though Kat and Alfie aren't together?
"Yes, definitely - obviously they've got Tommy and that means they'll always have a link. What's interesting now is how the dynamic has changed. Alfie and Kat have a certain dynamic, while Alfie and Roxy have a very different one.
"I think Rita Simons is now playing a different kind of Roxy, as the character is seeing somebody who she could spend the rest of her life with. At the same time, though, Roxy is feeling a little bit insecure because this relationship has happened very quickly. Roxy worries that Alfie might be on the rebound and could end up going back to Kat.
"Funnily enough, at the moment we're coming up to filming Valentine's scenes and there's a lovely story forming with these characters."
We've seen that there are a lot of fans of the Alfie and Roxy pairing. Did you expect it to be as popular as it has been?
"I had no idea that it would be popular. I just always assumed that people would want Kat and Alfie to stay together. But when we had the flirting scenes with Alfie and Roxy earlier in the year, a lot of people seemed to really like it.
"I think the viewers liked it because Kat was being horrible at the time. When Kat starts turning on her charm again, I think people are going to be saying, 'No Alfie, you need to be back with Kat!' Those are the dynamics we're playing at the moment, and we've even been filming scenes this morning for this storyline which are really interesting."
Is it true that you and Jessie didn't know the identity of Kat's lover for a long while?
"That is true - it was really kept under lock and key. I think that was more frustrating for Jessie than it was for me, because obviously the character of Kat knew who this person was, but Jessie didn't. We were happy to let it play out, though, because Kat flirts outrageously with all three Branning brothers, so we wanted the audience to make up their own minds about who the mystery lover was.
"There did come a point where myself and Jessie were brought upstairs and Lorraine Newman, our executive producer, asked if we wanted to know who the lover was. For me, I was still quite happy not to know, because Alfie was in the same position. But due to the shooting schedules and how we film scenes out of sequence, it was getting to the point where we had to know anyway.
"Once we found out who it was, it was a case of, 'Wow!'"
Are you relieved that the lover's identity hasn't been leaked?
"I am, yes, although we've still got a week to go! On Twitter there are people guessing and I imagine it's the same on Digital Spy - some guess right, and some guess wrong. Some have great theories and I think, 'Wow, I wish we'd thought of that one!' But certainly the press have played along and not exposed who Kat's lover really is."
The truth comes out just before Christmas. Are you busy in the actual Christmas episode too?
"Well, building up to Christmas, there's another little storyline which indirectly involves Kat and Alfie. The Christmas episodes are bloody good and Lorraine Newman has done a brilliant job. I think she's done a throwback to what Den and Angie were about. We're seeing families, turmoil, angst and anger.
"People ask, 'Why can't anybody be happy in EastEnders?', but that's because nobody does misery better than EastEnders! I think the viewers like to watch people having a really bad time and they feel good about themselves afterwards!"
Will you sit down to watch EastEnders on Christmas Day?
"Even before I was part of the show, it was always on in my house at Christmas - it was the Queen's Speech and EastEnders. It'll be the same this year, but I've got my whole family with me at Christmas - there'll be about 20 of us, so whether we'll get to hear any of the episode is another matter!
"But next Thursday, I've got a lot of family and friends coming around to watch the episode where Kat's lover is revealed. My wife knows who it is, but I've not told anybody else and we're going to do the big reveal round my house!"
Alfie and Michael are both in similar positions at the moment with broken marriages. Can we expect more scenes between those two?
"It's funny you should say that, because there's a lot coming up for Alfie and Michael. Watch this space and you'll see what happens in the New Year!"
> Read the latest 'EastEnders' spoilers and news
EastEnders reveals the identity of Kat's lover on Thursday, December 20 at 7.30pm on BBC One.