If there’s one thing science fiction fans can count on every year, it’s that a new Doctor Who Christmas Special will grace their TV sets on Christmas Day. Ever since 2005 when the show was revived for current audiences, viewers around the world have been treated to holiday adventures with the Doctor. Sometimes they’re tied to a larger story arc, while other times they’re inspired by classic Christmas tales. But it’s safe to say, they’re always a welcome addition to the holiday season.

This year the Twelfth Doctor and his companion Clara Oswald will face what’s being called their “Last Christmas.” According to the synopsis, while trapped on an arctic base under attack by creepy slime-creatures, they’ll enlist the help of Santa Claus (played by Nick Frost) to fight off their new enemies. The episode’s teaser trailer only showcased this battle, but the new trailer above reveals much more.

The trailer begins innocently enough with the appropriate Christmas jingle, but soon the Doctor appears, cryptically saying, “I’m back. Now, get inside the Tardis.” As we saw in the sneak peek, the Doctor has returned after a long time away because he says: “I know what this is. I know what’s happening. I know what’s at stake.” And Santa seems particularly interested in Clara, at least until the Doctor quickly gets her to leave, which could be our biggest clue about the episode yet.

It appears that what’s at stake may be Clara herself, judging by the ominous message she tries repeatedly to erase: “You are dying.” It’s true that although Peter Capaldi is already slated to return for season 9, Jenna Coleman has reportedly not signed on yet. Many are saying all the evidence points to this episode being Coleman’s farewell, and this new trailer certainly doesn’t disprove that idea.

There’s also the fact that the latest Doctor Who Magazine mentions their January issue will include a section where “Jenna Coleman reflects on her time as Clara Oswald.” While it could be a simple look back to the character so far, it does sound more like a feature for a character that will no longer exist.

Still, after so much secrecy surrounding whether Coleman will in fact return, it does seem rather odd that they don’t exactly hide it in the magazine or in this trailer.

What do you think, Screen Rant readers? Will this be Coleman and/or Clara Oswald’s last episode? We only have two weeks to find out.

The 2014 Doctor Who Christmas Special airs December 25, 2014 on BBC and BBC America.