In 2005, National Geographic Explorer investigated the brutal street gang known as MS-13 to uncover the truth behind what was thought to be an international crime "family" that knew no borders. It's been thirteen years since the original broadcast and MS-13's notoriety has grown significantly, but is its fearsome reputation justified? Explorer: World's Deadliest Gang Update investigates how MS-13 has developed over the past decade. Lisa Ling will reflect her experience making of the original film and comment on how MS-13 has changed since that time. Law enforcement officials and journalists will provide additional insight into the inner workings and motivations of what some consider to be the World Deadliest Gang.