EastEnders has revealed a first-look preview clip of the much anticipated flashback episode, set to air in September.
Some familiar characters will have new faces, as the show follows the Mitchell family before they made their names in Walford.
In 1979, Peggy Mitchell and her husband Eric have mixed ideas for how they want their sons Phil and Grant to grow up, while younger sister Sam is very young in the scenes.
Torn between their dad's encouragement of violence and showing the locals who's boss, Peggy is desperate to keep her boys on the straight and narrow - something fans know all to well doesn't work out.
In the clip, shown on Thursday's This Morning, the Mitchells are sat around the dinner table, with Peggy urging young Sam to eat her tea, while Eric pits the brothers against each other.
The rivalry we all know and love between Phil and Grant isn't quite there in these scenes, and instead the pair are playfully taunting each other.
Eric suggests the pair needed to prove they weren't losers, as Peggy express that "looking after your own" and "supporting each other" is all "you can do in the world".
There's a flicker of fear in Peggy's eyes too as Eric taunts her over Sam, possibly giving an idea of what went on in their marriage.
Viewers can see the full episode on Monday September 5, when the episode airs on BBC One.
Actress Jaime Winstone is taking on the role of Dame Barbara Windsor's iconic role Peggy for the episode, having portrayed Barbara in the BBC biopic Babs.
Speaking about the episode to This Morning, she spilled: "It's really about the family before the Mitchells became the Mitchells."
On the different side you see to Peggy, she added: "She's kind of a bit more vulnerable. You see her relationship with her boys and the foundations of her family."
Jaime also revealed what fans can expect from the special episode, and said: "It's a turbulent episode, there's lots to take in. It's an honour, it really is an honour."
EastEnders airs Mondays to Thursdays at 7:30pm on BBC One and BBC iPlayer.
