TV highlights: The history behind the 'Downton Abbey' castle

Back-to-back repeats of "Glee" (Fox at 8 p.m.) have the glee club kicking off its production of "Grease" with Rachel, Kurt, Santana and Cassandra July at the helm. Then, in a tribute to the 2003 film "Love Actually," Sam, Brittany, Jake, Puck and Artie all have very different Christmases.