THE PAGER PLOT – For the first time, ex-Mossad agents who led the exploding pager and walkie-talkie plot against Hezbollah, which garnered worldwide attention in September, detail their 10-year undercover op in an interview with correspondent Lesley Stahl. Meeting in Israel, the agents, who recently retired from service, share never-before-known details that caught Hezbollah fighters by surprise and ultimately spurred change across the region from Lebanon to Syria to Iran. Shachar Bar-On is the producer.THE IRON RIVER – With an estimated 200,000 to half a million U.S. firearms smuggled into Mexico each year through what's known as "the Iron River," correspondent Sharyn Alfonsi reports on Mexico's legal battle against American gun manufacturers and dealers and the efforts to curb gun trafficking to the cartels. Katie Kerbstat is the producer.JOY TO THE WORLD – At 25, with a powerful voice heralded as a once-in-a-generation talent, jazz vocalist Samara Joy is already making her mark in a genre that was last popular over 50 years ago. Correspondent Bill Whitaker caught up with Joy on her Christmas tour where she was joined by her family, a gospel dynasty. 60 MINUTES has a front row seat as the GRAMMY winner puts her own spin on the jazz classics. Heather Abbott and LaCrai Mitchell Scott are the producers.