Cora’s mother, Martha Levinson, is among the many wedding guests that descend on Downton for Matthew and Mary’s wedding. Lord Grantham discovers that his massive investment of Cora's fortune in the Grand Trunk Railway has failed, leaving the estate near bankruptcy. Matthew learns that he may stand to inherit a large amount of money from Lavinia's father, but he declares that it would be impossible to keep the money because he feels that he betrayed Lavinia and her father. Sybil and Branson, who remains highly vocal about his political beliefs, also manage to make the return to Downton for the wedding. Matthew ultimately chooses Branson to be his best man, and finally the long-awaited marriage becomes a reality.
Premiered in UK as Season 3: Episodes 1 and 2
Matthew receives a letter that Lavinia's late father had left for him explaining that even though he knew Matthew had broken Lavinia's heart, he still wanted him to have his money. Matthew finally accepts and saves Downton, prompting Lord Grantham to make Matthew an equal and joint master of Downton. Edith's wedding day finally arrives, but a late turn of events ruins everything. Mrs. Hughes receives some good news concerning her medical condition, much to the obvious relief of both Mr. Carson and Mrs. Patmore. In prison, Bates continues to have problems with a cellmate who tries to get him into trouble by planting drugs in his bunk.
Premiered in UK as Season 3: Episode 3
Branson is wanted by the police for his involvement in the burning of an aristocrat's home in Ireland. The Crawleys are outraged when he shows up at Downton without Sybil. After she eventually arrives safely, Lord Grantham convinces the Home Secretary to allow Branson to remain in England. Meanwhile, a mysterious conspiracy keeps Anna and Bates apart as they are no longer allowed to receive letters from each other and Anna is not permitted to visit Bates. Elsewhere, Ethel decides to let her son live with his grandparents in order to have a better life; and Carson recruits a new footman, Jimmy Kent, who attracts the attention of the female staff...and Thomas. There is a movement afoot for more widespread women's suffrage, and Edith writes a letter to the newspaper in support.
Premiered in UK as Season 3: Episode 4
Edith is thrilled when she is asked to write a regular newspaper column, but her family is not supportive. Matthew becomes convinced that Robert has been mismanaging the estate and discusses this with the family solicitor, George Murray, who supports Matthew's suppositions. However, Mary is angered when she discovers that he has been discussing this matter without her father present. Lord Grantham hires a famous obstetrician, Sir Philip Tapsel, as Sybil goes into labor. This upsets family physician Dr. Clarkson and Cora. The two doctors disagree over Sybil's care as Dr. Clarkson insists that Sybil is suffering from eclampsia and should be taken to hospital. However, Sir Philip argues that Sybil is fit and healthy. Despite the disagreement Sybil delivers a girl and all seems well - until later that night when things go horribly wrong.
Premiered in UK as Season 3: Episode 5
Branson decides to name his daughter Sybil and to baptise her as a Catholic. Robert is firmly opposed to both ideas but Mary and the rest of the family defend Branson's decision. Meanwhile, Violet devises a plan in hopes of repairing the rift between Robert and Cora, who are not speaking. Ultimately the plan works and Cora forgives Robert. Anna finds evidence that might prove Bates innocence, but another prisoner threatens his chances of freedom. Downstairs, with Mrs. Patmore's help, Ethel prepares a luncheon for the Crawley women. However, Lord Grantham becomes outraged upon learning that a former prostitute is serving lunch to his family - but Cora and the women ignore his protests.
Premiered in UK as Season 3: Episode 6
Bates is finally released from prison, to the delight of all except Thomas; who finds himself to be the victim of a trap set by O'Brien. Violet supports her granddaughter Edith's desire to become a journalist, much to the chagrin of Lord Grantham. Edith travels to London to meet with a magazine editor, and accepts his offer for a weekly column. Matthew and Robert continue to be at odds concerning Downton's management, leading to the resignation of the family's long time agent Jarvis. Miss Sybil Branson is baptised at a Catholic Church in Ripon, with the whole Crawley family in attendance. Downton Abbey's annual cricket match with the village takes place, bringing out Lord Grantham's competitive side. Violet's great niece, Lady Rose MacClare, pays a visit to Downton with her husband; and a wild trip to London reveals there is more to her than meets the eye. Carson controls Thomas's future, and Thomas finds an unlikely ally in Bates.
Premiered in UK as Season 3: Episodes 7 and 8
The Crawley family heads north, to Duneagle Castle in Scotland, to visit Lady Rose and her warring parents. Bates, Anna, Molesley, and O'Brien also make the trip. Gregson, the man who hired Lady Edith on at the newspaper, tells her that he is going to be in Scotland as well; which leads to some family dispute as to Gregson's motives. At Downton, the remaining staff looks forward to the approaching country fair, and Carson struggles to keep them concentrating on work. A new housemaid, Edna, joins the staff; only to be quickly fired by Mrs Hughes. Mrs. Patmore has a new romantic interest, but she soon wonders if the interest is in her or her cooking. Lady Mary goes into labor early, and travels home to deliver her baby - a son. Matthew rushes to join her and meet his heir; and tragedy strikes the Crawley family yet again.
Premiered in UK as Season 3 - Christmas Special 2012: "A Journey to the Highlands"
It's 1908 and Chicago born Harry Selfridge has arrived in London with a grand plan - to open the biggest and finest department store the world has ever seen. As the pressure builds on Harry to get the store up and running, obstacles continue to mount as well. A frosty reception from the British press, a business partner pulling out at the last minute, an ever-growing staff already on the payroll, and a wife and family arriving from the States - all serve to add stress to the situation. As opening day approaches, Harry pulls out all the stops to achieve his dream, at whatever the cost.
When Selfridge's finally opens, it is missing something - customers. Harry is worried, and knows he needs to capture the imagination of London to get some much-needed publicity. Ellen Love, "The Spirit of Selfridge's," herself gives Harry an idea. He decides he must get the first airplane to cross the Channel and its aviator into the store for a grand exhibition. Will Harry's high-flying ambitions be realized or will his dream crash before it ever gets off the ground?
Harry has a new idea: he wants to create a new beauty counter at the front of the store that sells perfume and even makeup – much to the consternation of some of his staff. Agnes runs into trouble with Reg, while Victor is still interested in her. Both Lois and Henri spot the threat of an ascendant Ellen Love, and Agnes helps Henri develop the new house perfume. Lady Mae asks Harry for a favor, and also reveals to Rose the truth about Ellen and Harry’s partnership - which spurs Rose to do something for herself.
Harry scores a massive coup when world-famous ballerina Anna Pavlova agrees to visit the store. Feeling coolness in Harry’s attention, a disgruntled Ellen Love leans on Frank for support. Reg’s violent tendencies reach breaking point in a dramatic and very public incident. Victor saves the day, and prevents George from getting into hot water in the loading bay. One of Harry’s closest employees is caught stealing, and a formidable new Head of Fashion arrives. Rose and Roddy’s friendship hits a surprising low when she reveals her true identity.
Harry revels in the display motorcar brought in for the store’s new motoring merchandise. Roddy surprises Rose at home – and young Beatrice witnesses something better left unseen! Harry visits a former employee, persuading her back to the store. Meanwhile, Agnes finds her romantic prospects are shifting. Ellen tells Rose a secret, while Beatrice confesses what she's witnessed. Harry hits rock bottom, reliving a traumatic childhood memory.
Harry finds himself in woeful circumstances, suffering more flashbacks to a specific moment in his childhood as a his family looks on. The store is on edge waiting for news about Mr. Selfridge, but instead shocking news of another kind effects the staff. Meanwhile, an impending Suffragette demonstration in the area forces the staff to pull together, and a grief-stricken employee makes a request of a colleague. Agnes and Henri's friendship deepens.
Literary giant and Spiritualist Sir Arthur Conan Doyle is in for a book signing when he persuades Harry to hold a séance in the store. Harry and Crabb work to deliver a valuable stock issue from the bank – with a little help from Lady Mae and Musker. Agnes is transferred to Fashion, Doris resolves to help an old friend, Miss Mardle is still agonizing over her relationship, and Kitty has a secret admirer. Rosalie goes to her first society soiree with Lady Mae, and what’s revealed in the séance forces Harry and Lois to have a major heart-to-heart conversation.
F. W. Woolworth tries to undercut his old friend and competitor, Harry, who gives the discount king a run for his money. The temperature rises with Agnes and Henri.
Tragedy strikes on the day polar explorer Sir Ernest Shackleton comes to the store. An even greater celebrity plans a visit, and Harry and Rose attend a shocking play.
When a psychic is found murdered, Inspector Lewis and DS Hathaway discover that the victim is really an Oxford psychology research fellow.
With Hathaway on vacation, Inspector Lewis is assigned a new partner to investigate the discovery of an elderly man's body in a field. Finding that the man had already been embalmed, the inquiry leads to a funeral home and those connected to it.
Lewis and Hathaway examine the brutal death of a chemistry professor recently released from prison. There may be a connection to the discovery of a murdered Oxford student reported lost for 15 years.