Clint Watts developed online relationships with terrorists and their sympathizers in order to understand and undermine terror networks. He also researched Russian efforts to influence U.S. elections. His new book is ‘Messing with the Enemy.’ Also, jazz critic Kevin Whitehead reviews a re-issue of a classic 1991 album by Anthony Braxton and his quartet, and film critic Justin Chang reviews the horror-thriller ‘Hereditary,’ starring Toni Collette.