An adventuring Swedish doctor takes on a decades-long medical mystery: What exactly was the 1918 flu? This week, we’re sharing an episode of Science Vs, a podcast from Gimlet, a Spotify Studio. They talk to Dr. Johan Hultin, Eileen Hultin, Dr. Jeffery Taubenberger, Ann Reid, Rita Olanna and Annie Conger.  To learn more about how CNN protects listener privacy, visit cnn.com/privacy