Oscar and Theo spot a boy named Rowan Stone who looks exactly like Oscar did as a child, leading to the suspicion that Rowan might be Oscar's grandson. Excited but cautious, they decide they need a DNA test to confirm the relationship. Theo plans to secretly collect a hair sample from Rowan without him noticing. Meanwhile, Rowan is deeply focused on playing chess, appearing serious and innocent. The episode ends with Oscar overwhelmed by the possibility of having a grandson, while Theo's covert attempt to gather evidence raises the tension about uncovering the truth.