In episode 3, Kathleen and Dermott have bonded, but she lies to him about who his real father is. Dermott worries that Tommy will tell Peter the truth and threatens him. Alfie realises that Kathleen lied to Dermott, which results in an argument. Dermott overhears them arguing about him not knowing the truth and Kathleen refusing to tell him. In episode 4, Agnes urges Kathleen to return to Spain. When Dermott learns of this he confronts Agnes about taking him from his mother. In episode 5, Agnes tells Dermott to keep Kathleen away from the christening of Bernie Kelly's (Susan Ateh) baby, but Dermott says Kathleen has made him feel welcome and invited him to meet his brothers in Spain, so Agnes reveals that Dermott has a twin sister. Dermott confronts Kathleen over this, who said she was waiting for the right time and insists there is nothing else that Dermott does not know.