Actress Natalie Cassidy is returning to 'EastEnders' as Sonia Fowler for a New Year special.
The Sun reports that Sonia comes to Albert Square when half-sister Bianca (Patsy Palmer) goes missing.
The Sun says a source revealed that Bianca disappears after a "huge confrontation".
The source said: "True to form, Bianca has got herself into big trouble while trying to protect her family and, scared about what might happen, she does a runner.
"Sonia then turns up unannounced - and drops the bombshell that she knows where Bianca is and what she is going to do next.
"But while Sonia is there other truths start to surface and viewers will find out what she and her husband Martin have been up to."
