Frankenstein (chapters 5-7)

Summary
Victor Frankenstein finally completed the construction of the body. He gave it life, but upon doing so was horrified by the creation. He ran away from it to his bedroom. He slept, but was soon awakened by the creature looking at him and mumbling unintelligibly. Victor then escaped outside, where he spent the rest of the night.
In the morning, Victor walked to town, where he saw his friend Clerval, who had come to study at the university.  They went back to Victor's apartment, where the monster was nowhere to be found. However, soon after Frankenstein began hallucinating and fell ill - having become crazy with fear of his creation - for several months.
When he at last became better, he received a letter from Elizabeth. She told him how well the family - including Victor's brothers, Ernest and William, and one of their servants, Justine - was doing, and begged him to come home.
Frankenstein planned to return to Geneva once he was fully healed. Though he improved physically, he was afraid of scientific apparatus, and hated talking to his professors about science. He was traumatized by everything related to the sight of the monster. Thus he and Clerval studied languages and writing instead.
Victor's return to Geneva was delayed by weather and other events. Nonetheless, during this time his spirits became increasingly high as Clerval helped him return to his humanity. He was becoming joyful and happy. Yet, he then received a letter from his father that said that when he, Elizabeth, Ernest, and William were out walking, Ernest and William went ahead to play hide and seek. William became lost, and was found strangled in the morning. Elizabeth thought it was her fault, because she had allowed William to wear a valuable picture of Caroline, and this may have been the motive for the murder.
Victor left for Geneva at once. Upon his arrival, a violent storm breaks out. He sees the silhouette of the monster behind the trees, and realizes that it must be the murderer. however, he doesn't tell his family, as he believes that no one can catch him anyway. However, when Justine is accused of the crime (because she had been sick the morning of William's murder, and was found with the allegedly stolen picture) he insists that she is innocent.

Notes
In the beginning of chapter five, there is a sudden change in Victor Frankenstein's personality. Upon seeing his creation become alive, he is disgusted and terrified of what was once his beloved obsession. It seems that he had to see the final product before realizing how awful it was. Victor reverts back to his original personality, which I believe was the author's way of then allowing him to connect on a personal level with his family after William's murder. He had to be distanced from the monster, so there was a definite difference between human and beast.
Also, a trend that I have observed in the book is one of irony. Just when the situation is terrible - such as when Frankenstein was ill and delusional - it takes a turn for the better - he then became extremely pleased with life in general. One can also recognize when a tragic event is about to happen; only after Victor is becoming joyful and has received a letter that the family is doing well, death strikes. I could predict that some woe was likely to befall a relative, as the letter Elizabeth wrote to Victor gave too many details that would be out of place in context, but could be used later in the story. Also, I knew that Victor would probably hear about it soon after he was feeling well and the book had acquired a tone of normality and happiness. In the same manner, I predict that Justine will be convicted, just because it is unfair and would be another blow to Frankenstein, who said that "...I was destined to become the most wretched of human beings."
Lastly, I had a few questions. First of all, I wonder what Victor used to make the monster come alive? Electricity? Also, why did Elizabeth, Victor's adopted sister, suddenly become referred to as his cousin? Finally, I wonder why Elizabeth feels so guilty for William's death? Could it be that she had a role in the murder?