In the summer of 1816, Mary Wollstonecraft Godwin, then eighteen years old, began to write the novel Frankenstein after she and her lover Percy Bysshe Shelley took part in a ghost-story competition at Lord Byron's villa by Lake Geneva. Over the next nine months -- a period which saw their return to England in autumn 1816 and subsequent marriage -- she (with Percy) drafted the entire novel in a form materially different from the two standard editions of 1818 and 1831 which were based on a later fair copy. Until now, no one has been able to read what Mary Shelley herself initially wrote in this original draft of the novel. Going back to the unique draft manuscript of the text held in the Bodleian Library, Charles E. Robinson has teased out Percy Shelley's amendments, isolating them from the story in Mary Shelley's hand. Both texts - with and without Percy's interventions - are presented in this edition, allowing us for the first time to read the story in Mary's original hand and also to see how Percy edited his wife's prose. The results are fascinating. We read a more rapidly paced novel that is arranged in different chapters. Above all, we hear Mary's genuine voice which sounds to us more modern, more immediately colloquial than her husband's learned, more polished style. To this day, Frankenstein remains the most popular work of science fiction. This edition promises to redefine the ways we read the story and perceive the act of its creation.