The brothers are stunned to learn that they have a half-sister, Scarlett (Kelsey-Beth Crossley), daughter of their mother's nurse, Carrie Nicholls (Linda Lusardi). Carl struggles to bond with her and he and Matthew try to buy her share of the business. Carl eventually softens but is uncomfortable around Carrie, as they had a brief relationship when he was a teenager but is grateful when Carrie helps evict Rosemary from Home Farm. Hari Prasad (John Nayagam) tells the police that he heard the King brothers discussing how they murdered Tom and Louise, his girlfriend, backs him up but the case collapses when Louise admits giving a false statement. After the acquittal, Carl admits to Jimmy and Matthew that he killed Tom. He reveals that he confronted Tom about Chas, hitting him when Tom called Chas names and then pushed him away, causing Tom to fall out of the window. Carl begins dating DCI Grace Barraclough (Glynis Barber) in secret, unaware of her plan to learn who killed Tom, but Carl won't say. Grace ends their relationship and Carl gets drunk, telling Jimmy and Matthew about the relationship so Jimmy takes Carl abroad to clear his head. However, on his return, Carl deliberately gets arrested for drink driving so he can see Grace and tells her that he killed Tom and decides to confess. Jimmy watches as Carl and Grace go to the police station and as Carl stops to answer his phone, Grace carries on and is hit by a lorry. Grace dies and despite telling the police that he is a killer, the police ignore him as they are more concerned about Grace.