What was happening when Mary Shelley wrote Frankenstein?

Mary Shelley was 18 years old when she wrote Frankenstein. She was on holiday with her future husband, the Romantic poet Percy Bysshe Shelley, at Lord Byron's home on Lake Geneva in Switzerland. The weather was poor so the group decided to have a ghost-story competition. Mary recounts in the introduction of the 1831 edition of Frankenstein, that she read the works of Johann Wolfgang von Goethe and Plutarch about the philosopher Empedocles, and in a dream, had the idea for her novel.