As "Downton Abbey" season 4 begins broadcasting in the US, season 5 is already gearing up for production.

Recently, executive producer Gareth Neame spoke with Zap2it on the progress of "Downton Abbey" season 5.

"We start filming Season 5 in about five weeks' time," said Neame. "We're working heavily on the episodes now. [Creator] Julian [Fellowes] has written the first four episodes, I've been working hard on those with him. Right now we're honing them ready for production."

Sadly, Neame is staying tight-lipped about any spoilers as to what "Downton Abbey" season 5 will bring.

"No," laughed Neame. "Not when season 4 has only just started [in the US]."

In case you're counting, this means "Downton Abbey" will begin filming in February. And sadly, it is unclear which of the cast members will return and who might get the axe.

One particular cast member that has fans worried is Maggie Smith as the Dowager, given her advanced age and rumors of her leaving the show last season.

Meanwhile, "Downton Abbey" season 4 continues to be a monstrous hit for PBS, with the premiere giving the channel record-setting viewership.

According to IBTimes, the premiere was seen by 10.2 million people in the US on Sunday, becoming the highest-rated drama premiere in PBS history.

“I’m so pleased that millions of viewers have returned to ‘Downton Abbey’ on their local PBS stations for what has become a post-holiday tradition.”