The Coming Swarm - Autonomous drones are being called the biggest thing in military technology since the nuclear bomb. David Martin reports.
The Hostage Policy - Lesley Stahl speaks to a counterterrorism adviser who admits U.S. failures in dealing with hostages, and to the parents of Steven Sotloff, a journalist who was kidnapped and killed by ISIS.
The Hunt for Planet Nine - At the farthest edges of our solar system, scientists have found evidence of a ninth planet. Bill Whitaker reports.