Libby Fox is back in EastEnders, but what is she hiding?

As if EastEnders wasn’t throwing enough twists at us with the shock revelation that Vincent Hubbard is a police informant (or is that a red herring, too?), there’s another surprise on the way.

It’s the day of Vincent’s birthday party and wife Kim (Tameka Empson) has dressed up in a sexy Santa suit.

Santa Baby! Kim dresses up for hubby Vincent (Jack Barnes/BBC

But she’s caught off guard by the return of niece Libby Fox.

Libby (Belinda Owusu) was last seen in the Square in August celebrating her birthday party when she received a call from sister Chelsea.

Sister Denise looks horrified by Kim's outfit (Jack Barnes/BBC)

Going outside to answer, fans discovered that Libby was hiding a big secret from mum Denise (Diane Parish).

We watched her leave the Square for Oxford with the mystery news weighing heavy on her shoulders, so the question is – why has Libby returned and what message has she got to tell?

Kim is pleased to see Libby but what secret is she hiding? (Jack Barnes/BBC)

EastEnders continues on BBC1 at 8pm on Monday