Act I
In the year 354 of the New Anthropogenic Glacial Period, members of an expedition led by Dr Walton discover a strange creature trapped in the ice. While his resuscitation is being performed, Walton examines it and wonders about the possibility of penetrating its memory and materializing its memories. The Creature comes back to life and stutters. Its stammering takes it back to the late 1810s, to Victor Frankenstein, who shaped this repulsive creature and brought it to life. Victor is called by Elizabeth, his beloved, and joins her. Together, they swear to love each other forever, while the Creature, hidden, watches them.
Villagers discover the existence of the hideous creature and are terrorised by it. They attack it and chase it away, without Victor and Elizabeth noticing. The Creature wanders into nature. It tastes a form of freedom and learns through its observations. It is particularly studying a blind old man and his family, whom it watches from a distance and so learns how to think and speak. The Blind Man gets to know the Creature. He cannot see it but he enjoys its company. He tells it that beings are naturally good and that the Creature should channel its aggression to rise to the rank of man. Felix, the Blind Man’s son, suddenly bursts in and, thinking he’s defending his father, violently attacks the Creature, who flees.
The Creature looks on as William, Victor Frankenstein's younger brother, plays in the wild with Justine, a family servant. Justine loses sight of the child. William then finds himself facing the Creature and his own death. In court, Justine is charged with William's murder and faces a hurl of insults from the assembled crowd. Elizabeth defends her, but there is evidence against Justine, not least the fact that she was holding the necklace that William was wearing. The Creature confesses to Victor of being responsible for William's death, but Victor remains silent during the trial and Justine is sentenced to death.
Act II
The scientists assembled around the Creature wish to suspend their exploration of the monster's memories. But Walton insists on continuing the experiment, for the Creature’s past stories shed light on their own present, and perhaps by reliving its traumas it will be able to find peace. Back in the Creature's memory, it has kidnaped Victor Frankenstein in a glacial cave. It argues that its cruelty is only the consequence of the suffering it has been inflicted. It begs Victor, its creator, to live up to the responsibility he bears towards the Creature by creating an alter ego with whom it share its life.
Elizabeth writes a letter to Victor: she misses him and cannot understand his silence. Henry Clerval is trying to get Victor, his friend, out of his laboratory. Victor is there busily creating a woman for the monster but then changes his mind and destroys his work in progress. The Creature takes Henry hostage to blackmail Victor: if he does not continue the work on its companion, then his friend will die. Faced with Frankenstein's refusal, the Creature slits Henry's throat and threatens to attack Elizabeth.
In conversation with Walton, the Creature says: ‘My heart was made to feel love and sympathy; but suffering turned it towards vice and hatred.’ Walton encourages it to forgive Victor for his arrogance, and thus to build another future, free from the memories of past violence. On her wedding bed, Elizabeth hears a gloomy song that frightens her: it’s the Creature approaching. When Elizabeth sees the Creature, she realizes that it is what Victor has been hiding from her. She does not reject it and, knowing that they are both condemned, shows it affection. The Creature attacks Elizabeth and kills her, then breaks into tears. Victor discovers Elizabeth's lifeless body and already knows that the Creature is the perpetrator of the murder. He curses this creation that was supposed to elevate him above all men but that has cast him down to beneath the earth.
Finale
The Creature pities Frankenstein, whom it nevertheless recognised as her father. Walton assures the Creature that all its memories have shaped its identity, and that it is therefore truly human. But the Creature, thus fully exercising its free will, refuses the company of the scientists and decides to sacrifice itself.