In April 1816 eighteen-year-old Mary Godwin travelled to Geneva with her lover, the poet Percy Shelley. (They had eloped and were to marry later in the year.) They stayed in Geneva for the summer with her half-sister, Claire, and another of England’s great poets, Lord Byron. But the weather was terrible. Instead of rowing on a calm and pleasant Lake Geneva, Mary wrote of a ‘wet, ungenial summer, and incessant rain [that] often confined us for days to the house’. It was during one such dark and stormy evening that a member of the travelling party suggested a game: each should write a ghost story. After several days of toying with different ideas, Mary Shelley conjured up the story of Victor Frankenstein, who creates a monster in a scientific experiment. Published in 1818, Frankenstein changed literary history and is today considered one of the first science fiction books. It still sells approximately 40,000 copies per year.