Cora's pregnancy throws the inheritance issue into doubt. Matthew must wait for an answer to his wedding proposal. O'Brien discovers more compromising information about Bates. Thomas leaves.

Bertie's circumstances change suddenly, leaving Edith uncertain whether to risk telling him the truth or keep her past a secret at all costs. Mary wonders if she can ever make peace with her sister as hostilities escalate, Spratt shows some hidden talents and Molesley's first day as a teacher does not go according to plan. Mrs Patmore's bed and breakfast attracts unwanted attention, leaving her in need of the Crawleys' help.

With the wedding approaching there is excitement in the air, but will Branson's plans rattle everyone? A decisive Anna forces Bates to think about their future.

An exciting offer for Edith divides opinion in the house. Isobel ends up throwing Ethel a lifeline. Ivy is attracting plenty of attention below stairs. Anna’s perseverance finally pays off for her.

Preparations are under way for Rose's wedding, but family tensions on both sides threaten to derail proceedings. Edith's arrangement with Marigold is happily working out, but how long can she and Cora conceal the truth from Robert? Denker reveals an unexpected side to her personality, which causes trouble for more than one of the servants. With the war memorial due to be unveiled, Mrs Patmore is still upset, but Robert has something up his sleeve. Branson comes to a heart-wrenching decision, and the storm clouds that have been gathering over Anna and Bates finally burst.

There's excitement in the house and village as the annual cricket match approaches, and the event brings out Robert's competitive side. Violet's great-niece Rose shows up but a trip to London reveals there is more to her than meets the eye. Matthew and Mary look like they are keeping secrets from each other. Thomas finds out that his future lies in Carson's hands.

Cora’s mother sweeps into Downton for Matthew and Mary’s wedding, but with the couple’s relationship under strain will they even make it to the altar? New footman Alfred strives to meet Carson’s high standards, under the watchful eye of his aunt O’Brien. Robert’s shocking news brings financial worries to the fore, on an unprecedented scale. Might he lose Downton itself and all it stands for?

Robert receives some shocking news from the front. Daisy's relationship with William moves faster than she would like. Vera threatens to expose old secrets.

Sybil puts herself in danger when a fight breaks out. Sybil's sisters notice Matthew's feelings for her. Mary is surprised by a marriage proposal. Bates clears his name over the missing wine but resigns rather than name the real culprit.

Rosamund comes up with a plan to help Edith deal with her problem, but Violet may be about to see right through it. Isobel is the object of someone's attention, while Mary asks Gillingham for a favour. Rose is frustrated when things do not go her way and Alfred realises too late that he may have made a mistake. Just as Bates and Anna seem to be getting over the worst, some unexpected news shakes her up.

The Great War unsettles life at Downton and surprising news about Matthew rocks the family. New maid Ethel irritates O'Brien - and Bates returns with devastating news for Anna.

Neville Chamberlain visits Downton for dinner, and is drawn into Violet’s plan to save the hospital, with distressing consequences for everyone. Andy finds an unexpected confidante while helping Mr Mason move into Yew Tree Farm, Mary is uncertain if she has met her match, Edith meets Bertie Pelham in London, and Spratt comes to Denker’s aid. Mrs Hughes struggles to keep Carson happy, while Mary thinks secrets are being kept from her.

Isobel finds herself at odds with Violet. Mary is introduced to a potential suitor but wants to be with Matthew. Anna works out who stole a valuable snuff box. O'Brien plans a way for Edith to get even with Mary.

Rosamund shows up at Downton following Edith's surprise departure. Rose is pleased to introduce Atticus and his parents to everyone. Anna and Bates think about a fresh start, now that that their problems seem to be behind them. Molesley is worried after Daisy becoming disillusioned with her studies. Mary and Blake seize a chance to send Gillingham a strong message.

Lady Mary's meddling gets Mr Carson into trouble with Mrs Hughes. Cora and Violet lock horns over the hospital takeover plans. Robert has a tough decision to make.

Sarah Bunting continues to cause waves above stairs, but this time she may have gone too far. On returning to Downton, Thomas suffers an inexplicable illness and Baxter suspects there’s more to it than he’s letting on. Violet reveals to Isobel the surprising truth of her past with Prince Kuragin. Mary comes to a decision concerning Lord Gillingham, but things don’t go quite as planned. When Rose’s father returns to Downton, he breaks news that will shock the whole family.

Amid the fallout from the eventful house party, Mary faces a pressing question about her future. Carson reveals surprisingly intimate details of his former life, and a trip to the bright lights of London sees Rose put the reputation of the Crawleys in jeopardy.

Simon Bricker returns to Downton to discuss the painting with Cora. Branson makes a difficult decision about Sarah Bunting. Rose encounters a handsome stranger. Determined to stop Isobel making the wrong decision about Lord Merton, Violet enlists the help of Doctor Clarkson. Charles Blake surprises Mary with a cunning plan to help her get exactly what she wants. Mrs Patmore seeks Carson's advice on a financial matter. Inspector Vyner returns with some ominous words of warning for Anna.

The house is made open to the public to raise money for the hospital, an act that divides opinions among the family and the servants. Tensions between Violet and Cora come to a head as a decision is made about the hospital takeover, Mr Dawes has a proposition for Molesley, and Baxter is thrown into turmoil by an unexpected letter. Carson is not happy with Thomas, while Mary and Edith hope to overcome their past and find new happiness with the men in their lives.

As Tom and Sybbie settle back into life at Downton, the family and servants are surprised by the return of another old friend in unexpected circumstances.

After Downton is turned into a convalescent home for wounded officers, Matthew brings a general to visit, but Branson has a surprise in store. And is Lavinia hiding something?

It is now 1925, when secrets and rifts threaten the unity of the family, while those below stairs are faced with social changes.

With the house recovering from the night’s dramatic events, Robert is faced with a very difficult decision. As Daisy continues to struggle with her studies, Mrs Patmore has an idea which might solve everything. Thomas has it in for Baxter. As Rose tries to convince Robert of the virtues of a wireless at Downton, Lord Merton continues his hot pursuit of Isobel. When Mary puts her reputation on the line, Anna is made a reluctant accomplice.

Branson's political views manage to get him into trouble while Sybil's loyalty is tested to the limit. Ethel finds herself being torn between head and heart as she makes a decision about her son's future. Anna is upset by Bates's silence and wonders what could be the cause. Carson looks for a new footman and a good-looking candidate called Jimmy creates interest below stairs.

After the death of the heir, Violet wishes that Robert's daughter Mary could inherit Downton Abbey.

Carson is finding it tough maintaining standards in the house, and the suicide of a young officer prompts Isobel to suggest converting Downton Abbey into a convalescent hospital.

Mary starts to get over the grief she is feeling, and takes an interest in the running of the estate. Lady Rose MacClare, Lady Flintshire's daughter, ends up in a predicament at a tea dance in York. Hughes attempts to convince Carson to heal an old wound.

Relations between Robert and Cora continue to be strained. Blake's scheming starts to come to fruition when Mary is unexpectedly pitted against her love rival. Edith receives some terrible news and decides to take drastic action. Following a mysterious tip off, Baxter becomes embroiled in the investigation of Green's death. Thomas' condition deteriorates, prompting him to finally reveal the truth to Baxter. Love is in the air for more than one member of the Crawley family.