We know the facts of Mary Shelley's life in some detail--the death of her mother, Mary Wollstonecraft, within days of her birth; the upbringing in the house of her father, William Godwin, in a house full of radical thinkers, poets, philosophers, and writers; her elopement, at the age of seventeen, with Percy Shelley; the years of peripatetic travel across Europe that followed. But there has been no literary biography written this century, and previous...