An explorer who rescues Victor from the ice, hears his harrowing story, and sets it down on paper in letters to his sister, Margaret Saville. Walton's quest for knowledge in the North Pole parallels Victor's search for education and enlightenment at Ingolstadt. Because he parallels Victor in this way, Robert Walton is a "double" of Victor, whose actions, by mirroring or contrasting Victor's own, serve to highlight Victor's character and various themes in Frankenstein.