 In September 2011, astronomer Donald Olson, after a visit to the Lake Geneva villa the previous year and inspecting data about the motion of the moon and stars, concluded that her "waking dream" took place "between 2 a.m. and 3 a.m." on 16 June 1816, several days after the initial idea by Lord Byron that they each write a ghost story.She began writing what she assumed would be a short story.With Percy Shelley's encouragement, she expanded the tale into a full-fledged novel.