The "Nova scienceNOW" magazine delves into a case of mass extinction some 250 million years ago; investigates the 1918 influenza outbreak, which killed as many as 50 million people; details the work of MIT roboticist Cynthia Breazeal's efforts to create "sociable robots"; and examines attempts to decipher 2000-year-old papyrus scrolls. Neil deGrasse Tyson hosts.