During Doctor Who‘s Comic-Con panel, departing showrunner Steven Moffat and soon-to-be-former star Peter Capaldi showed a quick teaser for this year’s Christmas special—which will be the final episode for both of them. The teaser doesn’t spoil a ton of things, but it does once again confirm that the episode will involve Capaldi’s 12th Doctor interacting with David Bradley playing the very first Doctor, with the two of them working together to fix some kind of broken moment in time. They’ll also meet up with a character played by prominent Doctor Who writer Mark Gatiss (making this his fourth role on the show), and a certain companion who seemed like she might be gone forever after the most recent season finale.

The special will air on Christmas day on BBC America, and the new season featuring Jodie Whittaker’s 13th Doctor will air at some point next year.