Henry and Victor return to Victor's apartment to find the monster gone. Victor finds the disappearance of his monster a source of joy and falls down in a fit of exhaustion from the release of anxiety over his creation. Henry spends the rest of the winter and spring nursing Victor back to health after the tumultuous fall. Henry advises Victor to write home, as a letter had recently arrived from his family in Geneva.
Victor and Henry begin their studies together, studying ancient and foreign languages in order to engage their minds. Both men are happy to be hard-working college students.Plans are made for Victor to return to Geneva in the fall, after his spring recovery, but weather and other delays make the trip impossible, and winter sets in. He revises his plans to depart in May.
William, the youngest in the family, has been murdered by strangulation. The family were out on an evening stroll near their home when the young boy ran ahead of the group. He was later found "stretched on the grass livid and motionless; the print of the murder's finger was on his neck." Missing was a locket that Elizabeth had given William of their mother.
When Victor arrives at the city gates, they are closed, so he must remain outside the city in Secheron until the gates are reopened at dawn. It is at this time that he realizes that he had been gone six years from home and that two years have passed since the creation of his monster.While near Secheron, on Mont Blanc, Victor catches a glimpse of the monster between flashes of lightning. Having a nagging feeling that the murder of his little brother could be the handiwork of his monster, Victor questions, "Could he be (I shuddered at the conception) the murderer of my brother?" The monster disappears when he realizes that he has been seen by his creator. Now fully believing that his creation murdered William, Victor knows that he cannot reveal the source of the crime without some serious inquiry about his creation. Thus, Victor is torn between revealing the monster and risking inquisition on his past or letting the criminal justice system free the accused.
Finally at home, Victor engages in a conversation with his family. He learns that Justine is accused of the murder with circumstantial evidence. He relays his assertion of Justine's innocence and states that she will be found not guilty. His words reassure Elizabeth in a time of great need.
Her sentence is to die by hanging the following day.Elizabeth and Victor go to see Justine in prison where both learn that Justine had given a false confession under stiff questioning. Justine goes to her death with no fear, leaving Victor to ponder the deaths of two innocent victims.
He tries boating on Lake Geneva and a trip into the Swiss Mountains. He escapes to the Chamounix valley region to rest and recover his senses.