Downton Abbey's fourth season is shaping up to be its most ambitious, judging by the reactions in the United Kingdom and the United States.
And Australian viewers are in for the same rude shock, as one of its darkest storylines is due to unfold soon.
Spoiler alert: After only one episode, Downton will introduce a predator into its mix of new and old characters and rock the very core of this almost sugar-coated portrayal of Britain's class dynamic of the early 20th century.
Charles Carson (left) with Cora Crawley, countess of Grantham, in the next season of Downton Abbey.
Despite a foreshadowing of the episode in November last year, which sent shockwaves across the internet, The Huffington Post wrote in its recap posted today: "None of it could have prepared us for what was to come next."
A US clinical psychologist and entertainment analyst argued that despite the shock, Downton didn't overstep the mark.
"This story line is already generating discussions and awareness of a topic that is too often considered taboo," wrote Dr Nancy Berk on Parade.com. "Yes, it was an uncomfortable episode of Downton Abbey, but if it helps bring attention to a critical problem and subsequently prevents future tragedies, then this might be the most important plot point of all."
Downton Abbey is one of the most watched dramas in the world with an estimated 120 million viewers. A record 10.2 million American viewers tuned in for the season premiere last week.
The show has been a huge ratings hit in Australia – Downton was the most watched international drama on all television stations last year.
In this latest season, Lady Mary Crawley (Michelle Dockery) has to come to terms with her widowhood just six months after her husband, Matthew, perished in a car crash. Her father Lord Robert Crawley (Hugh Bonneville) faces a number of business pressures with the death of Matthew having an effect on all of them. And all the while the world of 1922 and its modernity slip the characters by.
The fourth season is set to introduce several new faces to the Crawley family. Tom Cullen joins as Lord Anthony Gillingham, an old childhood friend of Mary whom she hasn't seen in years, Nigel Harman as Gillingham's valet Green, Dame Harriet Walter as Violet's friend Lady Shackleton, and Julian Ovenden joins as aristocrat Charles Blake.
There's also an Australian connection in the new series through real-life famed Australian opera singer Dame Nellie Melba, who will be staying as a house guest during the infamous episode. Melba is portrayed by New Zealand opera singer and actress Dame Kiri Te Kanawa.
The show will also introduce its first black character Jack Ross, portrayed by Gary Carr, the jazz musician and singer from Chicago's presence in the house and will no doubt be igniting some race-related controversy among certain characters.
Downton Abbey airs on Channel Seven.