When David Fajgenbaum was 25, he went from being a monster athlete to death’s door. Fajgenbaum found out he had a potentially fatal disease called Castleman which was attacking his immune system. The doctors couldn’t help him so Fajgenbaum found his own treatment. Now, he’s working on Covid. In this episode we talk about life, death and what to do when everything spirals out of control. “Now What?” is produced with the help of Steve Zimmer, Gabe Zimmer and Tay Glass. Audio production is by Nick Ciavatta.