SPOILER ALERT (if you have yet to watch Sunday’s Downton Abbey finale)…

Sunday’s conclusion of the third season of Downton Abbey capped off what’s been a tough year for the Crawley family. Story-wise, that is. The hit period drama killed off some key characters this season — one midway through and one in the last seconds of the last episode — and kept the audience hooked for record ratings. But what if co-creator Julian Fellowes, the man who writes every episode, were to leave? The idea was floated by Fellowes himself in an interview with The New York Times this week.

Fellowes recently signed on to write and produce NBC period drama The Gilded Age. The project, which has a script commitment with significant penalty attached, is a sweeping epic set in 1880s New York. Fellowes told the paper that if NBC picks up the show, he’ll be writing it when Downton “finishes.” He noted, “There are many hurdles that have to be cleared… But if (Gilded Age) goes, and if I’m doing a series at NBC, I would not be able to write all of Downton and all of that series at the same time.” Should Downton carry on, he said, “it would be with other writers. Perhaps with me supervising, but with other writers.” When I asked Gareth Neame about Fellowes’ comments, the exec producer and head of Carnival Films, which makes Downton, said, “We are currently filming Season 4 of Downton Abbey which is written entirely by Julian Fellowes. The show is in rude health and neither Julian nor I have plans to end it anytime soon.” (Neame is also exec producing the upcoming NBC/Sky Living drama series Dracula.)

It’s true that Downton was hotter than ever this year with the premiere episode on PBS in January almost doubling the series’ second-season premiere and the finale up 50% compared to last year’s season-ender — and that’s despite nearly unavoidable spoilers parading around the Internet since Christmas. In the UK, where the show airs first, Season 3 was the highest-rated yet for network ITV. Season 4 is expected to pick up six months after the dramatic end to Sunday night’s finale and focus on Lady Mary Crawley’s next steps in life. It starts airing in the UK in the fall.