In 1814, Regency-era London, Mary Wollstonecraft-Godwin is a 16 years old aspiring writer who works in the bookshop of her renowned father writer William Godwin, married in second terms after the passing of his first wife, philosopher Mary Wollstonecraft, with the too married by second time Mary Jane Clairmont, where Mary Jane's daughter of her first marriage Claire turns in a close and lovely stepsister for Mary.
When Mary and Claire travel at the house of one of William's friends in Scotland, Mary meets the 21 years old poet Percy Bysshe Shelley, rising instantly a love interest between them. Returning to London little time later, Mary unexpectedly meets Percy again when he appears at her house in order to ask William to take him on as an apprentice. Fascinated by Percy, Mary begins a bohemian and torrid relationship with him despite the opposition of her father and her stepmother, especially after they discover that Percy is married with a little daughter whom he supports but he loves no longer.