The TARDIS is as much a part of Christmas as turkey, mince pies, and mulled wine, and former "Doctor Who" showrunner Steven Moffat certainly knows his way around a festive adventure. This year's holiday offering, "Joy to the World", is the writer's ninth, and it comes with all the trimmings you'd expect.

Doctor Who Christmas special "Joy to the World" writer Steven Moffat and showrunner Russell T Davies dish on spoilers and script changes.

It’s not that Doctor Who’s festive episodes can’t be memorable; “The Husbands of River Song,” “A Christmas Carol,” “The Runaway Bride,” and more beg to differ. But I know it’s a holiday tradition in the U.