The year 1816 has, for generations, been known as “The Year Without a Summer”: the coldest, wettest, weirdest summer of the last millennium. If you read Frankenstein at school, you probably heard some version of the literary mythology behind that year. Mary Godwin (later Mary Shelley), having eloped with her poet-lover Percy Shelley, joins Lord Byron on the shores of Lake Geneva for a summer of love, boating, and Alpine picnics. But the terrible weather forces them inside. They take drugs and fornicate. They grow bored, then kinkily inventive. A ghost story competition is suggested. And boom! Mary Shelley writes Frankenstein.