'Downton Abbey' recap: The season finale

Fix yourself a pot of tea or, better yet, pour yourself a stiff drink. This is the recap of "Downton Abbey's" season finale and we're going to be here a while.But, as a service to our young readers, let's start with a near tweet-able summary: Mary sings beautifully. Tom said goodbye. (We'll believe it when we see it.) Robert is seriously ill. Or not. Edith smiled. Mr. Carson and Mrs. Hughes, aw. We still don't know who killed Green. (I can't even remember Green.) Denker and Spratt formed a law f...