它讲述的是危险而充满魅力的诗人Percy Shelley和17岁的玛丽·沃斯通克拉夫特之间充满激情的爱情故事，这也让玛丽·雪莱在一年后写下科学怪人。
故事发生于十九世纪的瑞士，大名鼎鼎的诗人拜伦（加布里埃尔·伯恩 Gabriel Byrne 饰）隐居在位于瑞士乡间的一座古堡中，在这里过着放荡不羁自由自在的生活。一天，他的好友雪莱（朱利安·山德斯 Julian Sands 饰）登门拜访，同时和他一起来的，还有雪莱年仅19岁的年轻情妇玛丽（娜塔莎·理查德森 Natasha Richardson 饰）、玛丽同父异母的妹妹克莱尔（米丽亚姆·西尔 Myriam Cyr 饰）以及拜伦的私人医生约翰（蒂莫西·斯波 Timothy Spall 饰）。当晚，古堡外狂风大作，暴雨袭来，这样一种阴森可怖的场面，让一屋子的人决定围在一起讲恐怖故事，但渐渐的，那些故事里的妖魔鬼怪，似乎打破了虚构与现实的壁垒，现身于古堡之中。
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.
Lady Caroline Lamb, dissatisfied in her marriage, has an affair with the dashing Romantic poet Lord Byron.