For two hundred years a noble Venetian family has suffered from an inherited disease that strikes their members in middle age, stealing their sleep, eating holes in their brains, and ending their lives in a matter of months. In Papua New Guinea, a primitive tribe is nearly obliterated by a sickness whose chief symptom is uncontrollable laughter. Across Europe, millions of sheep rub their fleeces raw before collapsing. In England, cows attack their owners in the milking parlors, while in the American West, thousands of deer starve to death in fields full of grass.

What these strange conditions–including fatal familial insomnia, kuru, scrapie, and mad cow disease–share is their cause: prions. Prions are ordinary proteins that sometimes go wrong, resulting in neurological illnesses that are always fatal. Even more mysterious and frightening, prions are almost impossible to destroy because they are not alive and have no DNA–and the diseases they bring are now spreading around the world.

In The Family That Couldn’t Sleep, essayist and journalist D. T. Max tells the spellbinding story of the prion’s hidden past and deadly future