A Hollywood sneak preview of series three unveils sparks between Downton Abbey's Dame Maggie Smith and newcomer to the show Shirley MacLaine.
The new season finds the Crawley family in the middle of a financial crisis and even though Matthew and Mary got engaged at the end of the last series, there is tension between the couple, played by Dan Stevens and Michelle Dockery.
US channel PBS showed brief snatches from the new series to the Television Critics Association ahead of a discussion with actors and producers from the worldwide smash hit.
They took a breather from filming in London to meet journalists in Beverly Hills in California.
Their trip to the US came after a strong showing by Downton Abbey in this year's Emmy nominations with 16 bids.
In one scene provided by PBS, Hugh Bonneville's character Robert Crawley, is seen telling his American wife Cora (played by Elizabeth McGovern) about a disastrous financial investment.
Matthew and Mary, whose turbulent relationship initially led to a happy marriage, are shown having an argument in which she accuses him of being disloyal to the family.
Tension between MacLaine's Laura and Dame Maggie's Violet, also appears to be a significant plot in the third series.
Downton Abbey's creator Julian Fellowes said the new series is set over two years in the early 1920s.
Another key plot line is the fate of John Bates, Robert Crawley's valet, who was convicted in the last series of murdering his wife.
Bonneville made his support for his servant evident. At the end of the panel discussion, the actor took off his shirt and revealed a T-shirt he was wearing with the words "Free Bates" on it.
MacLaine also joked that Dame Maggie Smith and herself had been "lovers in another life".
Then she shared Dame Maggie's anecdote of their meeting about 40 years ago backstage at the Oscars, after MacLaine failed to win a trophy.
"Do you know what you did, dear?" Dame Maggie reminded her. "You tucked right into that chocolate cake and said, '(Expletive), I don't care if I'm thin ever again'."
Also taking part in the discussion were Dockery, McGovern, Joanne Froggatt and executive producers Gareth Neame and Rebecca Eaton.
Stevens was one of the actors absent due to filming in London, which carries on right through August.
Downton Abbey returns to the UK in September.