On Sunday night, Downton Abbey premiered its third season on PBS' Masterpiece Theatre, and an extremely devoted American audience cheered with glee. The British costume drama, which follows the aristocratic Crawley family and their household staff as they navigate the years following the sinking of the Titanic, has been an unexpected water-cooler hit for PBS, which airs "new episodes" of the series months after they've already premiered on the U.K.'s ITV. But much like the characters at the center of its story, there are plenty of secrets buried in Downton Abbey. Here, 5 things you probably don't know about the worldwide TV hit:

1. Laura Linney, who introduces Downton Abbey on PBS, is intended to feel like a "headwaiter leading guests to a fabulous meal." Masterpiece Theatre executive producer Rebecca Eaton told The Huffington Post that the role of Masterpiece Theatre's "host" is to "create an atmosphere and provide context for the programs that follow. […] Laura Linney is as elegant and classic as the dramas she introduces." So that clears that up.

2. Gillian Anderson almost played Lady Grantham. According to Entertainment Weekly, The X-Files' Dana Scully revealed to TV Guide Magazine that she had been offered the role of Cora Crowley, also known by the title Lady Grantham, but decided to turn it down. The part eventually went to Elizabeth McGovern, who earned an Emmy nomination in 2011.

3. Andrew Lloyd Webber unsuccessfully attempted to buy Highclere Castle, where the majority of Downton Abbey is filmed, in 2010. "I think it has more to do with Andrew Lloyd Weber’s desire to hang his art collection somewhere. Maybe it might help with his estate duties," said Lady Carnarvon, who currently resides in the ancestral home, at the Los Angeles Times. "He was not a friend and, therefore, might not be aware of our own art collection."

4. A prequel series is reportedly on the way. Downton Abbey creator Julian Fellowes originally planned to write a novel detailing the courtship between Lord Grantham and Cora Crowley, but the recording-breaking success of the series encouraged ITV, which airs Downton Abbey in the U.K., to pick up the story for a separate series, which will air sometime after Downton Abbey ends. The Telegraph reports that a Downton Abbey play or a feature-length film might also be produced.

5. The series nearly doubled its U.S. viewership between season two and season three. TV Line reports that Downton Abbey's season three premiere on PBS Sunday night earned a series-high 7.9 million viewers in the United States, up from the 4.2 million who tuned in for season two. Season three has already finished airing in the U.K., so spoiler-averse U.S. viewers should tread very, very carefully over the next few weeks.