It takes more than one amnesiac burn victim to deter audiences, apparently: The season two finale of Downton Abbey earned PBS its highest overnight ratings since 2009’s Ken Burns National Parks, as 5.4 million people tuned in to find out whether Mary and Matthew might ever get their acts together. (And also whether Bates would hang.) Downton’s ratings were up 25 percent from its first season, regularly doubling the PBS average viewership, and the show made significant headway with the under-50 demo. See, sometimes delicious mediocrity is enough.