Kat returns to Walford to spend Christmas with Stacey. Alfie follows with the children, and it is revealed that Zoe does not want to see her. Kat is surprised when Sister Ruth visits her, and reveals the truth about her son, whom the nuns called Luke, and Ruth reveals he was adopted by an Irish family. Kat realises Mo knew about Luke, and argues with Mo and Charlie. Charlie has a heart attack and dies, leaving Kat devastated. Belinda returns and blames Kat for Charlie's death. Alfie tells her that he has a brain tumour, but assures her it is benign. Kat vows to attend Charlie's funeral, despite her sisters not wanting her there, but on the day, Stacey is mentally ill so Kat stays with her at The Queen Vic. She makes amends with Belinda and tells her about Luke. Belinda then reveals that Viv once took the family (minus Kat) to a village in Ireland called Redwater, and Viv visited a church and left crying, blaming Kat for this, and Belinda saw a couple with a boy watching them leave. Kat then finds out information about Redwater but she and Alfie then leave for Spain.