After an interesting diversion last week with Matt’s linear and focused story, The Leftovers returned to its scattered, dour ways in “The B.J. and the A.C.” Christmas is a difficult time of year for many, often bringing up complicated emotions related to family, faith and brokenness. It’s a time that is prescribed to be merry, leaving those who aren’t all the more alienated. Of course, in the world of The Leftovers, there’s not even a pretense of merriment, and no one could possibly be more alienated, so the show’s Christmas-focused episode was naturally a cold one. Hit the jump if you want something to drink — water? Coffee? Drano?