En 1814, Mary Wollstonecraft Godwin entame une relation passionnée et scandaleuse avec le poète Percy Shelley et s’enfuit avec lui. Elle a 16 ans. Condamné par les bien-pensants, leur amour tumultueux se nourrit de leurs idées progressistes. Invitée par Lord Byron, qui lance un jeu d'écriture, Mary a l'idée du personnage de Frankenstein, avec lequel elle révolutionnera la culture populaire.
Le 16 juin 1816 en Suisse, la nuit la plus celebre de la litterature fantastique moderne. En effet sont reunis dans une luxueuse villa qui surplombe le lac Leman deux illustres poetes, lord Byron et Percy Shelley, leurs compagnes Claire Clairmont et Mary Shelley et le docteur Polidori, medecin de Byron. Le docteur propose un concours d'histoires "gothiques". C'est ainsi que naquirent les deux mythes de la litterature fantastique "Frankenstein" et "The Vampyre". "Gothic" est le recit des etranges evenements qui se deroulerent cette nuit-la dans la villa Diodati.
Lady Caroline Lamb, dissatisfied in her marriage, has an affair with the dashing Romantic poet Lord Byron.
In the summer of 1816, Percy Shelley, his mistress Mary, and her stepsister Claire visit Lord Byron at Lake Geneva. Byron challenges each to write a horror story, and Mary begins her novel, Frankenstein. She imagines the monster becoming real, and for the next six years, as tragedy befalls those around her, she believes the personification of her imagination is the cause. Against this backdrop, Claire has Byron's baby then is estranged from him and barred from her daughter. Byron and Percy continue their friendship, the one self-centered and decadent, the other wildly idealistic. The Shelleys take up residence near Pisa.
Authors Lord Byron, Mary Shelley (née Godwin) and Percy Shelley get together for some philosophical discussions, but the situation soon deteriorates into mind games, drugs, and sex. It is a fictionalization of the summer that Lord Byron and the Shelleys, together with Lord Byron's ex-lover Claire Clairmont and his Doctor John Polidori, spent in the isolated Villa Diodati by Lake Geneva. It is there they devise a contest to adduce the best horror story to kill the dullness of summer. It is also there that one of the world's most famous books was given life—Mary Shelley's Frankenstein.