Mary Shelley had travelled in the region of Geneva, where much of the story takes place, and the topics of galvanism and other similar occult ideas were themes of conversation among her companions, particularly her future husband, Percy Shelley. The storyline emerged from a dream. Mary, Percy, Lord Byron, and John Polidori decided to have a competition to see who could write the best horror story. After thinking for weeks about what her possible storyline could be, Shelley dreamt about a scientist who created life and was horrified by what he had made. She then wrote Frankenstein.