Broadway legend Aaron Lazar shares an update on his fight against Amyotrophic Lateral Sclerosis (ALS); Sen. Laphonza Butler (D-Calif.) talks about the Democratic National Convention; ABC News medical correspondent Dr. Darien Sutton answers viewer questions; bestselling author and executive producer Karin Slaughter ("Will Trent"); chef Alex Guarnaschelli features food from the U.S. Open.