[SPOILER ALERT] Natasha O'Keeffe on the Set of "Sherlock" Christmas Special

The Brits sure do have a funny idea about what makes for a good Christmas special. Here in America, we tend toward, say, country singers warbling “Silent Night” with a children’s choir. Over there, they tend to prefer more nightmarish yuletide tales, it seems. It’s a little graphic so be warned as you scroll down. …