Alison is a deaf caterer who uses her lip-reading skills to help the police gather information about a gang of criminals. In episode 4, she visits Liam at his apartment, where she confronts him about their previous encounter. Liam apologizes for disappearing and invites her in, explaining that he had to move due to Braden needing his other place back. Alison presses him for details about his activities but he remains secretive, only assuring her that 'brain trumps brawn' and expressing his desire to see her daily.

At the start of episode 4, DS Ashleigh Francis warns Alison to be cautious around Liam. Alison inquires about the potential legal consequences for Liam if he is charged with conspiracy, and Ashleigh suggests that if Alison can help the police apprehend the gang before they escalate to violence, it might improve Liam's situation.

In episode 4, Alison and Liam have a complex interaction. Liam apologizes for his previous disappearance and invites Alison into his new apartment. Despite his secrecy about his activities, he expresses a strong desire to see her every day. Alison, however, tells Ashleigh that she is merely leading Liam on, suggesting she does not have genuine romantic feelings for him.

While specific scenes from episode 4 are not detailed in the portrayal of lip-reading challenges, the series generally emphasizes the real-world difficulties and limitations of lip-reading. This approach adds authenticity to the narrative, avoiding the depiction of lip-reading as a magical ability.

Episode 4 of Code of Silence has received mixed reactions. Some viewers find it 'okay' but note that the series is becoming more predictable and 'sillier' as it progresses. Critics, however, have praised the series for its unique perspective and authentic portrayal of challenges faced by the deaf community, contributing to its overall positive reception.