In our cover story, Conor Knighton looks at how public libraries have evolved in the 21st century. Plus: Dr. Jon LaPook looks at the role of those on the front lines of public health; Mo Rocca profiles entertainer Sandy Duncan; Mark Whitaker looks at two legends being inducted into the National Baseball Hall of Fame; Anthony Mason talks with former President Barack Obama and rocker Bruce Springsteen about their podcast and book projects; Seth Doane explores the history of the "Popemobile" at the Vatican Museums; and Martha Teichner hunts for treasure – beautiful glass orbs, hidden across Block Island.