Downton Abbey” fans were treated to a Q&A with a few cast members and producers of the show Saturday at the Writers Guild that ended with a trailer of the final season of the PBS hit.

In a wide-ranging discussion, writer-producer Julian Fellowes, producer Gareth Neame, stars Elizabeth McGovern, Hugh Bonneville and Laura Carmichael revealed little about the final episodes, including if fan faves Shirley MacLaine and Paul Giamatti will return.

Bonneville and Carmichael said they would miss Highclere Castle, which stands in for Downton Abbey.

“High Clere castle is a pretty nice office to come to work,” Bonneville quipped.

Moderator Mary McNamara of the Los Angeles Times asked if the cast had seen the series finale, to which Fellowes promptly replied, “I haven’t written the finale yet.”

Going back to the beginning, Fellowes and Neame talked about how the idea for the show started. The pair were “celebrating the failure” of a pitch to the BBC at a really bad restaurant. Instead of eating, they came up with the idea for a TV series that would be similar in era to “Gosford Park,” for which Fellowes won the 2001 original screenplay Oscar.

“Julian didn’t seem eager at the time, but the idea came to life very quickly,” Neame said.

“Once you imagine the characters, you have accepted the job,” Fellowes added. He said that there were about 350 American heiresses who married into English aristocracy around the turn of the 20th century and he wanted to follow up with them 50 years later. McGovern, an American married and living now in the U.K., was perfect to play the part.

Maggie Smith, McGovern and Bonneville were three cast members they wanted and got from the beginning. “Very often there’s this thing where you pretend the actors you got were the ones you wanted,” Fellowes said, but in their case it was true.

Neame called Smith “Julian’s muse,” to which Fellowes rejoined, “I never had to explain funny lines to Maggie.” She and Bonneville were among cast members who could effortlessly move between comedy and drama, he said.

“Maggie Smith is a joy, so kind and funny to work with,” Carmichael said, while Bonneville added with a smile, “You may as well retire, because Maggie Smith will steal every scene.”

As for letting the Dowager Lady Grantham have a suitor, Fellowes said, “I enjoy love and I like the idea that everyone has an emotional life, whether successful or not. I like older characters to have emotional lives. In Movieland, women’s sex lives end at 30, men go on to 78.”

That goes for Carson the butler and Mrs. Hughes the housekeeper, who got engaged at the end of the previous season. Even McGovern’s character, Cora, had an interesting arc beyond being just the mother.

“The power of the show is that people are people,” Fellowes said. “Some American heiresses are very nice and some are not. I didn’t want a show where the  people below-stairs are put-upon.”

He had to explain again, as he has in past years, about the deaths of Lady Sybil and Matthew Crawley because the actors who played them — Jessica Brown Findlay and Dan Stevens  — wanted to move on.

“We don’t sit at our desks plotting how to kill characters,” he said.

So was Bonneville worried when he read about Lord Grantham’s chest pains in the script? “I skipped to the end,” he said.