Meanwhile, in a flashback scene, Ruth purposefully walks into resus where a patient lies on the slab - it's Mary, a woman in her thirties, who looks very much like Ruth, and wears a heart-shaped necklace. In a later session, Ruth starts to open up to Andrew, explaining who Mary is - a former patient who Ruth suspected of having Munchausen's Syndrome during their series of fraught encounters.
Later, Ruth meets a fellow patient, Jim, and forms a bond. Jim is desperate to listen to music so that he can practise for a concert at the Royal Albert Hall, but to Ruth's annoyance the staff won't allow him to have earphones. Not to be thwarted, Ruth takes Jim to the chapel where there is a piano for him to practise. He plays for her and one thing leads to another… until they are discovered by staff.
As the story of Mary unfolds, Andrew realises that it could hold the key to Ruth's problems. And when Jim tries to harm himself after their encounter, Ruth realises that it was her fault for enabling him to play music. But just who is Mary and how can she help Andrew get to the core of Ruth's mental problems? And is Ruth ready to stop fighting those who are treating her and accept that she needs help?