Through Robert Walton, Victor's story is filtered by an unbiased third-person narrator. Walton is separated from the action, so he can remain impartial in areas where Victor cannot. Walton's letters begin and end the novel, creating a frame for Victor's and the creature's narratives. In this way, Walton combines the most important qualities found in both Victor and his creature. He balances the curious yet arrogant nature of Victor with the sensitive side of the creature.
As an Arctic explorer, Walton, much like Victor, wishes to conquer the unknown. However, when he finds Victor near death on the icy, vast expanse of water, he listens to Victor's bitter and tormented tale of the creature. He postpones his own mission and glory to help a fellow man. This makes him reconsider continuing his own mission, if it would put his crew in danger. When the creature appears at Victor's deathbed, Walton fails to fulfill Victor's dying wish to destroy the creature. Instead, he does what Victor continually failed to do throughout the novel: he listens to the creature's anguished tale with compassion and empathy.
Robert Walton's story, which frames that of Victor Frankenstein, provides a certain realism that mitigates the fantastic element of the narrative of Victor Frankenstein and his creature by lending the narrative credibility as someone else also ventures into a new scientific realm.
The characters of Victor Frankenstein and Robert Walton mirror each other in their desires to conquer new dimensions, but Walton's desire to conquer the frozen regions is less extreme than Victor's attempt to create life. After Walton hears the story of Victor's efforts, he realizes that he must temper his desires and consider the safety of his crew: "The die is cast; I have consented to return if we are not destroyed."
There is also a credibility lent to the ventures of Victor Frankenstein as the reader learns that there are others who are also willing to move in the unknown. The themes of isolation and the imperfection of science as compared to nature are underscored by their repetition in the frame story and the main story.