Iran has executed a second protester related to the anti-government demonstrations gripping the nation. But even in the face of brutal punishments and possibly even a death sentence, the protests have continued. The regime vows to continue its crackdown. Christiane's first guest says that executions are a tactic of repression from an outdated playbook. Hadi Ghaemi is the Executive Director of the Centre for Human Rights in Iran.  Next, we hear from Princeton professor Seyed Hossein Mousavian, a former Iranian diplomat and chief nuclear negotiator.  Also on today's show: Lizzie Gottlieb, director of Turn Every Page, which reveals the extraordinary, 50-year relationship between her father, editor Robert Gottlieb, and Robert Caro, one of America's most widely read political biographers.To learn more about how CNN protects listener privacy, visit cnn.com/privacy