When Nicola Mitchell (Laura Doddington) arrived in EastEnders, a small scene outside the pub confirmed she knows Zack Hudson (James Farrar).

We learnt they had a brief fling years ago, but their connection hasn’t really been revisited since.

In upcoming episodes though, Zack’s whole world changes in a matter of moments as he discovers he’s Barney’s (Lewis Bridgeman) biological father.

When the new week begins, Sharon Watts (Letitia Dean) realises Bianca Jackson (Patsy Palmer) knows her secret and tries to take control of the matter, but circumstances prevent her from speaking out.

Following her failed attempt to come clean, Sharon talks to Zack about her secret, but then realises someone has been listening into their conversation, which later turns out to be Barney.

Wanting to protect his sister, Zack promises Sharon that he’ll find a way to stop Barney from speaking out.

He heads to Harry’s Barn to confront him, but their conversation takes a turn when the young lad starts bleeding from the wound he sustained during the Queen Vic explosion.

At the hospital, Zack joins Nicola and Teddy Mitchell (Roland Manookian), but when a conversation about blood groups starts, Zack is suspicious and wonders if Nicola has been keeping a secret from him.

After a conversation with the nurse, Zack confronts Nicola and asks if he’s Barney’s dad and eventually, she says yes.

Perhaps unexpectedly, Zack heads back to Walford and chooses to drown his sorrows in some booze, struggling to take in the information.

To make matters worse, Zack then receives a phone call from Whitney, but what does she want?

Zack’s life has changed forever but without best friend Martin Fowler (James Bye) around for support, and Sharon clearly occupied with something else, can he get through this alone?