Meanwhile, Suki Panesar (Balvinder Sopal) is on a mission to bring down guilty stepson Ravi Gulati (Aaron Thiara); and Ian Beale (Adam Woodyatt) tries to convince Cindy (Michelle Collins) to accept Bobby (Clay Milner Russell).
Grieving Jay Brown (Jamie Borthwick) meets another woman as he looks for ways to cope, while Stacey Slater (Lacey Turner) is also in need of support over her stalking ordeal.
Finally, Sharon Watts (Letitia Dean) and Karen Taylor (Lorraine Stanley) have a harsh exchange, before Sharon receives some big news.
Read on for all your EastEnders spoilers for 18th - 21st September 2023.
7 EastEnders spoilers next week
1. Alfie Moon reveals he's been diagnosed with prostate cancer
Alfie finally makes peace with Kat after recent events, but she's pained when he explains that he can't be at her wedding to Phil. Later, Keanu Taylor (Danny Walters), who has learned Phil's secret, accidentally spills the beans to Alfie, who is horrified.
Alfie heads to the Arches to get the truth from Keanu; and Alfie is soon intent on exposing what he's found 0ut. He ends up storming to Peggy's and punching Phil, only for Alfie's own turmoil to emerge. Alfie tells Phil that he lied about his all-clear, and that he does have prostate cancer.
Alfie explains that he's due to have a prostatectomy that day, and pal Linda Carter (Kellie Bright) hears about the hospital trip from Mitch Baker (Roger Griffiths). Linda puts two and two together and arrives to support Alfie with his procedure.
Will Alfie open up to his loved ones, or keep his illness under wraps with only Phil and Linda in the know? And what about Phil's secret - will Alfie keep it to himself?
EastEnders is working with Prostate Cancer UK and Macmillan Cancer Support on Alfie's story, and you can read more on the character's state of mind ahead of the emotional scenes.
For those affected by the storyline and looking for someone to talk to, details of help and support are available at bbc.co.uk/actionline, or you can all for free, at any time to hear recorded information on 08000 560 190
2. Will Kat Slater marry Phil Mitchell as the groom hides a big secret?
Phil struggles to contain his guilt as Kat excitedly prepares to become Mrs Mitchell. Louise (Tilly Keeper) calls Kat to tell Phil that Keanu can't have access to little Peggy, Phil marches over to the Arches and lies that he's already told Kat about Emma and that Kat has forgiven him.
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Phil hopes that this will keep Keanu quiet, but with Keanu spotting Kat's happy mood and guessing Phil's fib, he threatens to tell her everything, before involving Alfie!
Meanwhile, Jean Slater (Gillian Wright) arranges a surprise hen party for Kat in The Vic against her wishes. The ladies toast to her last night of freedom, but when the big day dawns, Kat is panicked when Phil arrives late to the registry office without Alfie - who it seems has promised to be there after all.
Will Kat marry Phil, or might she discover his betrayal? Or could she learn about Alfie's condition, making her realise that he's still the man of her dreams?
3. Suki Panesar plots to destroy Ravi Gulati
Suki convinces Denise Fox (Diane Parish) to give a statement on the incriminating video of Ravi, against Jack Branning (Scott Maslen) and Chelsea Fox's (Zaraah Abrahams) wishes. But due to a lack of physical evidence and Suki's previous failed statement, the police dismiss the two women.
Denise tries to cut ties with the Panesars, but then Suki reveals her new plan to secretly record Ravi's confession! Suki meets Ravi in The Albert to carry out her scheme, but an ill-timed phone call from the prison interrupts.
Ravi is soon threatening more harm to her family if Suki doesn't keep quiet, and Suki pleads with Denise to help put Ravi away once and for all. Denise refuses, fearing for her family's safety.
As the week continues, Suki regrets telling Nugget (Juhaim Rasul Choudhury) about his father. Ravi senses that something is up with son Nugget, but a chat with Zack Hudson (James Farrar) leads Ravi to wrongly assume it's merely teen angst.
Nugget tries to persuade Denzel Danes (Jaden Ladega) to skip school, but Denzel refuses. Suki then finds Nugget, and the youngster goes to Walford East to confront Ravi about Suki's claims. Nugget later takes refuge at the Panesars, while Ravi arrives in search of his son. But will Ravi be brought to justice?
4. Ian Beale urges Cindy to accept Bobby
As Bobby struggles living with Sonia Fowler (Natalie Cassidy) amid a movie night, Kathy Cotton (Gillian Taylforth) speaks to Ian, imploring him to convince Cindy to let Bobby move back home.
But with Cindy uncomfortable over Bobby's presence, even knowing that he was a child when he killed her daughter Lucy (Hetti Bywater), all hell breaks loose.
Can Ian persuade Cindy to back down, or will Ian find himself forced to choose between his son and his partner?
5. Troubled Jay Brown seeks support from stranger Nadine
Jay returns home after a night of walking, unable to sleep due to his grief over his wife Lola (Danielle Harold). But Jay is warmed when he meets a woman named Nadine (Jazzy Phoenix). Later, he apologises for making an abrupt exit the day before and takes Nadine for a drink at The Albert.
The pair put aside their misunderstanding, and Nadine invites Jay back to hers, where she tries to seduce him. Jay refuses her advances, and when Nadine returns to the Square, Jay worries about being seen with her. What exactly is going on as Jay continues to spend time with Nadine?
6. Stacey Slater finds support from Jack Braning as Theo Hawthorne lurks
After the police failed to keep Theo in custody, Stacey is terrified when she bumps into him in the Square gardens. Jack consoles Stacey, and agrees to help her get an interim stalking protection order. Jack also promises to be on hand if anything should happen, to deter Theo.
But although Stace tries to put aside her anxiety to celebrate Kat's wedding, Theo arrives in the middle of the hen do. Stace keeps up a bravado, but once she's alone, it's clear how scared she is by Theo's presence. Will Jack's support be enough to help Stacey take action against her stalker?
7. Sharon Watts gets an offer
Karen and Sharon continue to clash over access to Albie, and a verbal altercation ensues. Sharon then hears about a job opportunity in Abu Dhabi from Dorian, and she later steps in when Keanu vows to spill Phil's secret, issuing Keanu with a threat.
But what does Sharon say? And might she consider a new life? Perhaps not yet, if so, as Sharon will be around for Christmas drama...
- EastEnders' Shane Richie: Alfie 'broken' over Kat amid prostate cancer diagnosis
- EastEnders 2023 summer preview: 5 spoilers from Chris Clenshaw
- EastEnders trailers for Cindy return tease Kathy showdown: "You're dead!"
- EastEnders' Michelle Collins confirms flashbacks and Cindy Beale breakdown
EastEnders airs on BBC One from Monday to Thursday, and from 6am on BBC iPlayer. Visit our dedicated EastEnders page for all the latest news, interviews and spoilers. If you’re looking for more to watch, check out our TV Guide and Streaming Guide.
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