In this episode, we find out why masks are an important tool in the fight against this new coronavirus. We’ll also talk about this unusual time we’re living through and how to deal with the uncertainty of it all. Plus: Kara and Gilly debut their first single. They’re hoping it’s a viral sensation (pun very much intended). And, of course, a new mystery sound and a Moment of Um that answers the question: Why do sharks have to keep moving to stay alive?