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.

Avalanche: It took 10 hours for rescue crews to reach Hotel Rigopiano after an avalanche buried the Italian resort. No one expected survivors, but rescuers never gave up on those who'd been buried alive.

Enhancing the Bike: Bill Whitaker investigates whether pro cyclists have used secret bike motors to win races -- like the Tour de France -- in a sport notorious for its culture of cheating.