Prions are biological anomalies – self-replicating, not-alive little particles that can misfold into an unstoppable juggernaut of fatal disease. Prions don't contain genes, and yet they make more of themselves. That has forced scientists to rethink the "central dogma" of molecular biology: that biological information is always passed on through genes. The journey to discovering, describing, and ultimately understanding how prions work began with a medical mystery in a remote part of New Guinea in the 1950s. The indigenous Fore people were experiencing a horrific epidemic of rapid brain-wasting disease. The illness was claiming otherwise healthy people, often taking their lives within months of diagnosis. Solving the puzzle would help unlock one of the more remarkable discoveries in late-20th-century medicine, and introduce the world to a rare but potent new kind of pathogen. For the first episode in a series of three about prion disease, Short Wave's Gabriel Spitzer shares the science behind these proteins with Emily Kwong, and explains why prions keep him awake at night.