Tom Branson, portrayed by Allen Leech, is a widowed son-in-law of the Earl of Grantham who finds love again with Lucy Smith, played by Tuppence Middleton. Lucy is the illegitimate child and sole heir of Lady Maud Bagshaw, a character brought to life by Imelda Staunton, who is well-known as Queen Mary's Lady-in-waiting.
In a surprising twist, Violet Crawley, portrayed by Maggie Smith, the formidable Dowager Countess of Grantham, shocks her family by introducing George Murray, the family lawyer. He unveils a captivating piece of history: Violet had once been gifted a villa in the South of France by the Marquis De Montmirail decades ago. Violet passionately decides to pass this villa down to her great-granddaughter, Sybbie, the daughter of Tom and the late Lady Sybil Crawley.
As Violet reminisces, she reveals that her visit to the Marquis was quite the affair, leading her to ponder his motivations. The family is left to speculate his intentions while a new threat emerges; the current family associated with the deceased Eduoard decides to legally challenge the Crawleys over the villa's ownership.
In another fascinating development, a film production company approaches the family to use Downton as the backdrop for a silent film titled The Gambler. Initially hesitant, Robert Crawley, played by Hugh Bonneville, ultimately agrees to the arrangement after his eldest daughter, Lady Mary Talbot, argues that the revenue would be beneficial for repairing Downton's roof.
To maintain oversight, Lady Mary insists that Mr. Carson, portrayed by Jim Carter, accompany Robert, despite his reservations about the film project. As preparations begin, excitement fills the household, but the arrival of the film crew quickly disrupts the daily life at Downton.
Anna Bates, played by Joanne Froggatt, along with Daisy, eagerly anticipate meeting the leading actress, Myrna Dalgleish, portrayed by Laura Haddock. However, their admiration quickly fades when they realize Myrna’s behavior is far from gracious; she treats the staff rudely, which does not sit well with Robert.
The new Marquis De Montmirail extends an invitation to the family for a visit to the villa, insisting they stay with him rather than at a hotel. Though Violet can’t make the journey, Tom, Lucy, Lady Bagshaw, Robert, and his wife Cora, played by Elizabeth McGovern, alongside their daughter Edith, portrayed by Laura Carmichael, accept the invitation, leaving Lady Mary behind to oversee the film's production with the help of Mrs. Hughes.
As the story unfolds, Butler Thomas Barrow confides in Mrs. Hughes about his sexuality, adding depth to the character dynamics. Upon arrival at the villa in France, tension rises when Madame Montmirail contests Violet's ownership, even as the Marquis insists it legally belongs to her. He shocks Robert by suggesting that their shared birth dates could imply a familial connection.
Amid concerns over Cora’s health, Robert grapples with the possibility of losing his mother and wife. Back at Downton, the production of The Gambler collapses when silent films fall out of favor, prompting Lady Mary to suggest dubbing dialogue instead. The casting of actor Guy Dexter, played by Dominic West, and the complications surrounding Myrna's accent lead to creative solutions despite the setbacks.
As the film is salvaged, Cora takes charge in helping to refine Myrna's American accent, which proves pivotal for her career. The subplot involving Edith, stifled in her role as a marchioness, indicates her desire to get back into her work at the London magazine she owns. The Downton servants step in to aid in the film's completion, showcasing their loyalty and resilience.
Eventually, revelations about Violet's connection with the Marquis come to light, though they bring little solace to Robert, who faces increasing stress amidst his family's turmoil. In a heart-wrenching conclusion, Violet's health deteriorates, leading to her passing, surrounded by loved ones, leaving a poignant legacy behind. As life at Downton continues, the family evolves, welcoming Tom and Lucy back with their child, and honoring the memory of the beloved Dowager Countess with her portrait hanging in the main hall.
