— During the rainy summer of 1816, the Year Without a Summer, the world was locked in a long cold volcanic winter caused by the eruption of Mount Tambora in 1815. Mary Shelley, aged 18, and her lover (and later husband) Percy Bysshe Shelley visited Lord Byron at the Villa Diodati by Lake Geneva in Switzerland. The weather was consistently too cold and dreary that summer to enjoy the outdoor holiday activities they had planned, so the group retired indoors until dawn.