Victor decides to leave Geneva forever. While visiting the graves of his family he swears revenge, and then he hears the monster's laughter, and its voice calling Victor a "miserable wretch." Victor pursues the monster, but it escapes into the darkness.
The monster's revenge is successful; now Victor suffers isolation as it does.
For months, Victor tracks the monster northward into the frigid Arctic regions, led by clues and taunting notes the monster leaves behind. Victor chases the monster onto the frozen ocean with sleds and dogs, and comes within a mile of the monster's own sled, but then the ice breaks up beneath Victor's sled.
The barren arctic is a perfect symbol of isolation and the power of nature. A man in this tundra is utterly alone and entirely at the mercy of nature.
This is the point at which Walton's ship rescued Victor. The narrative returns to the present. Victor, knowing he's dying, begs Walton to take vengeance on the monster if he should happen to see it.
Victor has finally told his story and secret to a sympathetic audience. But is there any difference anymore between Victor and the monster except appearance?