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,

After setting up the Time Hotel the Doctor is staying at—a business of myriad gateways currently set to send guests to every Christmas in history—we’re quickly whisked through a bunch of those doorways as he follows a strange suitcase hopping between handcuffed,

The pair unpack "Joy to the World," including the cultural reference they couldn't ignore. "It's a piece of our history now," says Moffat.