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.

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.

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.

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.

Preparations for the wedding of Mr Carson and Mrs Hughes are under way. Edith meets up with an old acquaintance. Spratt has something to hide.

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.

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?

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.

Cora's tries to set up Mary with Evelyn Napier, who falls for his friend instead, with significant consequences for the household. Bates takes action to help cure his limp.

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.

Edith's wedding day arrives but will her enthusiasm be able to convince the family that Strallan's age doesn't really matter. Mrs Hughes awaits her results. Anna manages to make a breakthrough as she tries to help Bates. Mary decides to take matters into her own hands to secure the estate's future.

The Crawleys watch Henry compete in a motor racing event, an occasion that leaves Mary reeling. Violet hatches a plan which surprises the family and delights Miss Denker, and learns more about Amelia's intentions in befriending Isobel. Molesley and Daisy rise to the challenges of examination day, Andy's secret is brought to light, Thomas feels isolated, and Mrs Patmore and Mrs Hughes teach Carson a lesson.

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

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.

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.

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.

Matthew Crawley and his mother Isobel arrive at Downton, and have difficulty settling in. Carson is mortified when confronted by his past. Violet attempts to promote a match between Matthew and Mary. Isobel is elected to serve on the hospital board.

Tempers are left on edge after a kind gesture by Isobel backfires. Mary attempts to fight Branson's corner after his decisions are put under scrutiny. Robert and Cora's relationship feels the strain and Violet attempts to make them see things differently. Some extreme measures are taken by Bates.

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 story moves on to 1924, when the first ever Labour government heralds a sea change that is felt throughout the nation - nowhere more so than at Downton. A suggested plan for a war memorial unexpectedly pits Carson against Robert and Mrs Hughes. Young Jimmy the footman is the object of some unwanted female attention. Thomas gives Baxter an ultimatum. Branson's growing friendship with someone Robert considers quite unsuitable causes concern. After the tragedy she has been through, Lady Mary now seems ready to find love once more. Cracks appear in Edith and Tim Drewe's special arrangement as she struggles to keep her emotions in check - something which may have disastrous consequences for the entire household.

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.

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

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.

Mrs Hughes finds herself the focus of speculation when she meets a former suitor who makes her question her position. Violet and Isobel clash over a medical ailment affecting Molesley. Carson is concerned there is a thief at work in the grounds.

Carlisle threatens to ruin Mary if she jilts him. A major comes to stay - but is he really who he claims to be? Bates learns that Vera has succeeded in scuppering the divorce.