Mary and her sister Jane have always longed for a handsome young man – preferably a poet – to whisk them away from their strait-laced life. And in the spring of 1814, Percy Shelley walks into their father’s shop – like an angel of deliverance. Seduced by Shelley’s radical ideas – freedom from marriage and the binds of established religion – the girls flee with him to Europe, much to the horror of their family and the society of their times. Plagued by gossip, jealousy and suspicion, Mary begins to suffer from freakish imaginings and horrific visions. When tragedy strikes and Mary realises that her dreams are now nightmares – her angel is a monster.