She began writing what she assumed would be a short story. With Percy Shelley's encouragement, she expanded the tale into a full-fledged novel.  She later described that summer in Switzerland as the moment "when I first stepped out from childhood into life".  Shelley wrote the first four chapters in the weeks following the suicide of her half-sister Fanny.  Byron managed to write just a fragment based on the vampire legends he heard while travelling the Balkans , and from this John Polidori created The Vampyre (1819), the progenitor of the romantic vampire literary genre. Thus two legendary horror tales originated from the conclave.