When Tanya's behaviour begins to spiral out of control next week, Max (Jake Wood) arrives back on Albert Square to find out what has gone wrong back at home. However, he doesn't return alone as he has older brother Derek in tow.
As Derek reacquaints himself with Max's family, it's clear that Tanya (Jo Joyner) isn't pleased to see him, while Rainie (Tanya Franks) also seems to be uncomfortable around him.
While Max takes some time to get to the bottom of the current chaos in the Branning clan, Derek heads out to meet Jack - but his plans change when he spots Pat Evans (Pam St Clement) on the Square.
Pat is visibly nervous to see Derek, who follows her into her house despite her making it clear that he's not welcome. Derek starts to bring up some of their past, but they're soon interrupted by Carol (Lindsey Coulson) - who is even less happy to see him and warns that he should stay out of her life.
After his frosty reception, whether Derek will be able to work his way back into the Branning fold remains to be seen.
The return of Max and Derek forms part of a special 'Branning Week' which launches on Monday and sees EastEnders air five nights in a row for one week only.
With Max back, it isn't long until the truth about Tanya's cancer is finally exposed to her loved ones - but the bombshells don't end there as she also reveals a secret that she has kept for many years.
Derek - now played by Jamie Foreman - previously appeared briefly on EastEnders in 1994 with Terence Beesley portraying the role.
When Foreman's casting was announced in August, executive producer Bryan Kirkwood said: "Loyal EastEnders viewers may know that the fearsome Derek Branning, eldest son of Jim, has been a shadowy presence looming over the rest of the family for years. So it's a real coup to sign Jamie Foreman to play the biggest, baddest Branning brother."
Meanwhile, an EastEnders insider commented: "Out of all the Brannings, Derek is the one that most people fear. Although he can be charming, he will be the one that can out-alpha almost any man in Albert Square - maybe even Phil. He is going to cause a lot of disruption to his family."
EastEnders' Branning Week begins on Monday at 8pm on BBC One.
> EastEnders announces Derek Branning casting
> EastEnders' Max to return in huge Branning Week
> Full details of Branning Week are now live in our EastEnders spoiler section