Unbeknownst to the convent, Gertrude begins leading a double life, venturing into the city and pursuing sexual encounters with random men. Gertrude also begins to intravenously abuse morphine and heroin that Sister Mathieu steals for her from the hospital. A change in her personality is noted by Dr. Poirret, as Gertrude begins to mistreat patients and revel in reading gory hagiography on the lives of tortured saints to them. Gertrude successfully manages to have Poirret fired from the hospital. While Gertrude is in a drug-induced state, Sister Mathieu's grandfather, a patient at the hospital, is bludgeoned to death with a lamp, and his body thrown out a window so as to appear as a suicide. Sister Mathieu finds Gertrude's veil with his body, but, pledging her loyalty, assures Gertrude she will not implicate her, promising to burn it to hide the evidence.