The Doctor Who Christmas special re-introduced fans to Jenna-Louise Coleman as Clara Oswin Oswald.

And then the episode killed this companion off. Yes, again.

What the heck is going on here? Even the two-hearted doctor himself doesn't appear sure, at least not based on the following BBC promo. It teases new episodes to come, many of which will be based on the mystery of Ms. Clara Oswald. Watch now and prepare for plenty more Doctor Who in 2013...

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.