Edith discusses her romance with Bertie with Cora. She voices her concern about telling Bertie the truth about Marigold. Cora encourages her to tell Bertie the truth.
Sgt. Willis talks to Mrs. Patmore about her first guests at the B&B. He explains that her first guests were actually there under false names; it was a man and woman committing adultery. The woman's husband is suing the adulterous man and Mrs. Patmore may be called as a witness. He warns her that her B&B may be considered a house of "ill repute" since rumors have spread that adulterers go there. Mrs. Patmore is horrified.
Robert and Rosamund discuss Violet's absence. They spot Edith and Cora walking and each wonder whether Bertie will still marry Edith if he learns the truth about Marigold.
Tom accompanies Mary into town. They spot a newspaper showing that Bertie's employer Lord Hexham has died and wonder whether he'll be out of a job.
Molesley and Baxter discuss Molesley's new job at the school. Baxter encourages Molesley to tell Mr. Carson, rather than ask, that he needs the time off. Molesley is hesitant, doubting his abilities and fearful that the job won't work out.
Isobel and Lord Merton discuss her invitation to his son's wedding. Isobel is still suspicious, though Merton believes it is a result of Amelia's influence. Isobel hints that Amelia may not be as sweet and kind as Merton believes.
The story about Mrs. Patmore's B&B spreads upstairs and downstairs, with everyone laughing about it (except for Carson, who is perturbed by the scandal). Mary and Anna discuss Bertie's potential unemployment.
Mr. Dawes delivers the news that Daisy passed each of her papers with high marks.
The family gathers and discusses the fact that Bertie's cousin/employer has died. Edith joins them, reporting back that she spoke to Bertie and he is on his way back. She also reveals that Bertie is the new marquess of Hexham, shocking everyone. Mary is annoyed by this development, but the rest of the family is thrilled for Edith and Bertie.
Mr. Carson criticizes Mr. Molesley's decision to request off from 2 to 5pm every day to take a shot at teaching. Mrs. Hughes cuts him off and encourages Molesley to go for it.
The Crawleys laugh about Mrs. Patmore's problem. Tom tells Mary he heard from Henry. Mary tells him not to ask Henry to come to Downton. Tom gently suggests that Mary is miserable without Henry, annoying her.
Edith worries to Rosamund that Bertie is stopping by Downton to break up with her. Rosamund encourages Edith to come clean to Bertie about Marigold as soon as possible.
Robert and Cora discuss Edith's situation, with Robert gleeful about Edith's opportunity and Cora worried.
Mary and Tom walk around on the grounds, discussing the estate. Tom asks Mary to let him invite Henry over. Tom insists that she loves Henry. Mary is convinced that for someone in her position, a bad marriage would be catastrophic. Mary brings up Marigold and Tom admits that it is true. He tries to convince Mary to get back together with Henry, but Mary gets angry and refuses.
Rosamund, Cora, and Robert discuss Edith's situation. Robert leans towards not telling the truth, while Rosamund insists she must or Edith will risk wrecking Bertie's reputation and family name. Bertie and Edith arrive. Bertie becomes emotional over his cousin's death.
Carson commands that the servants disregard Bertie's request to refer to him as Bertie and only refer to him as Lord Hexham. Thomas gets bad news about a job rejection and confides in Baxter. He is despondent and doubts he'll have a future. Baxter teases him and he walks off. She looks worried about his response.
Over dinner, Mary rudely brings up Bertie "settling things" with Edith before he leaves. Bertie hopes to resolve their engagement before leaving. He tells the family about his mother, who is a stern character, and the family laughs. Edith looks nervous.
Mrs. Patmore and Mrs. Hughes are accosted by a newsman as they approach her B&B. Mrs. Patmore grows hysterical when her niece tells her that all the bookings were canceled due to the scandal.
Mr. Dawes introduces Mr. Molesley to his class of students. He is visibly nervous, and the kids laugh at a doodled drawing of him that gets passed around, throwing him off.
Bertie and Edith discuss Bertie's nervousness over the huge change in his life. Bertie asks her to help him by marrying him. Edith expresses doubts. She asks whether his mother is very stern, and he confirms it. Edith again delays giving Bertie an answer to his proposal.
Bertie and Tom entertain the children and family with a puppet show. Mr. Talbot arrives and all the family except Mary greets him warmly. Mary tries to imply that Mr. Talbot will not want to stay overnight, but he says he would love to. Henry gives Bertie his condolences.
Mr. Molesley is unable to maintain control over his class. They chatter and play loudly and ignore his time charts.
Mary and Tom argue. Henry arrives. Mary criticizes how Henry would handle being outranked by his own stepson, though Henry insists it wouldn't bother him. Henry tells Mary he's going to make getting rid of him as hard as possible, angering her.
Mary interrupts as Rosamund, Cora, and Robert discuss Edith's problem. She angrily wonders why they invited him to stay the night and tells them to get rid of him as soon as possible.
Molesley admits to the other servants that his first day of teaching was a challenge. They encourage him to keep at it.
The family chats after dinner and Robert quizzes Bertie about going back to Tangier to reclaim his cousin's things. He is impressed to hear that Bertie is flying part of the way there. Edith warns Henry that Mary is a handful. Tom criticizes Mary for implying that she is refusing Henry for his lack of money and status. She storms off and Henry follows.
Henry apologizes for showing up unannounced. He comments to her that it seems apparent that she is refusing him because of his lack of rank and money and criticizes her for it. Mary is offended at his implication that she is a gold-digger and storms off, Henry calling after her.
Anna and Bates discuss Mary's relationship and Anna admits that she was wrong about Henry and Mary's relationship.
Bertie and Edith prepare to say goodnight. Bertie encourages Edith to give him an answer to his proposal. Edith insists that she loves him, but tells him that her life is not as simple as it used to be. Bertie decides to take that as a yes and kisses a nervous-looking Edith.
The next morning at breakfast, Mary comes down and finds Henry gone. She is confused and distracted at that news. Robert steps out to write letters. Bertie announces that he and Edith have news. Edith stops him, saying it isn't the right time. Mary and Edith begin to argue, Edith claiming that Mary cannot stand it when things are going better for Edith. Mary retaliates by coldly implying the truth about Marigold. Edith confirms it. Bertie is shocked into silence and quickly leaves.
Rosamund suggests that the family go to have tea at Mrs. Patmore's B&B, to bolster its reputation. Mrs. Hughes encourages the idea.
Isobel and Amelia have a tense tea. Isobel flatly tells Amelia that she will not rekindle her romance with Lord Merton without express encouragement from Larry Grey.
Mr. Carson harshly criticizes the idea of the Crawleys becoming mixed up in Mrs. Patmore's scandal, insulting Mrs. Hughes for going along with it. Mrs. Hughes brushes him off and encourages Mrs. Patmore to accept the Crawleys' offer.
Tom and Robert discuss whether Mary's admission was an innocent mistake. Bertie takes a walk with Edith before heading out. He tells her that his only problem with the news is that Edith didn't trust him enough to confide the news. Bertie tells Edith that he doesn't believe he could spend his life with someone he didn't trust, who didn't trust him. Edith apologizes to Bertie and Bertie says goodbye to her.
Tom rebukes Mary, yelling at her for ruining Edith's life. Mary insists that she didn't know that Edith hadn't told Bertie the truth. He rejects that claim. He accuses her of being a bully and a coward. Mary is taken aback.
Baxter, on her way out, spots Thomas looking very forlorn and heading into his room. She looks concerned.
Mary goes to see Edith in her room, where Edith is packing up to leave. Mary continues insisting she didn't know Edith hadn't told Bertie. Edith unloads on Mary, yelling at her and calling her a bitch. Before she departs, she tells Mary that Henry is perfect for her but she's too stupid and stuck up to see it.
Mrs. Patmore visits with the family and tells them that she doesn't want to get them mixed up in her scandal. The family is surprised and ask whether Carson believes this. He says he does. Robert disagrees and confirms that they will return Mrs. Patmore's loyalty with loyalty to her. This brings Mrs. Patmore to tears and she departs.
Mrs. Baxter walks with Molesley to school. She encourages him to tell the kids that he is a servant at Downton, before they or their parents find out about it. Molesley comments on Thomas' odd mood and Thomas spontaneously wishing him well. Baxter realizes something and rushes back to the house, where she frantically looks for Thomas. She and Andy find him in the bathtub with his wrists slashed. She sends Andy for Mrs. Hughes and a doctor and moves to bind Thomas' wounds.
Mrs. Patmore dismisses Daisy to go to the school with Mr. Molesley. She sees Andy running and tells him where Mrs. Hughes is.
Edith drives to town and spots Tom. She asks him to drive her to the train station so he can drive the car back, as she's planning on going to London and hasn't said goodbye to anyone. Tom offers to talk to Bertie on her behalf, but she turns him down.
Mrs. Hughes, Andy, and Mrs. Baxter carry an unconscious but alive Thomas out of the bathroom and into his bed.
Daisy shows up at the schoolhouse and overhears Mr. Molesley giving an impassioned speech about education to the kids. He admits that he is in service, giving them hope for their future. The kids are now respecting him and engaged in learning.
The Crawleys are beginning to lay into Mary about what she did to Edith when Carson enters serving the family tea. He admits that Thomas cut his wrists, chilling the family. Mary harshly comments about Robert's decision to cut Barrow loose, upsetting Robert.
At the servants' dinner, Carson tells the other servants that Thomas has taken ill but not what caused it. Daisy reveals to everyone that she peaked in on Molesley's lesson and the kids were spellbound. The servants applaud him.
Anna and Mary discuss the events of the day, with Anna assuring Mary that Barrow will recover. Anna asks about Henry, setting Mary off. Mary insists that he is not right for her, and Anna asks whether she's sure. Mary gets upset that no one believes she knows her own mind.
At The Sketch office, Edith confides in Laura about the end of her romance with Bertie. Laura expresses her condolences. They discuss the advice columnist, Mrs. Jones, who will be coming into the office to negotiate a pay raise, given the success of the column. They joke about having a signal (the word "bananas") if they think the person is the real Mrs. Jones or a stand-in.
Mary and George visit Barrow in recovery. George brings him an orange. Mary asks about Barrow's loneliness. They each wish one another well, and Mary and George leave when Anna enters the room to care for Barrow.
Mrs. Patmore and Daisy plan on heading to her B&B. Mr. Carson continues to criticize getting the Crawleys involved, annoying Mrs. Hughes. Mrs. Hughes calls him an old curmudgeon. Carson wonders if she is beginning to dislike him, but she assures him that he is her curmudgeon and kisses him.
Tom goes to meet Violet as she arrives at the house.
Violet meets with Mary privately. She asks why Mary did what she did to Edith. Mary explains that she's sorry. Violet admits that Tom said that Mary does these things because she is unhappy. Mary tearfully admits to Violet that the real reason she refused Henry is because of his dangerous career and that she couldn't handle being a widow again. Violet encourages Mary to choose a husband for love. Violet tells Mary to make peace with Edith and to make peace with herself. They hug.
The family goes off to have tea at Mrs. Patmore's B&B. Mary and Tom remain behind. Mary reports to Tom that she sent Henry a telegram and that he will hopefully arrive by tea time. Tom asks about her reconciliation with Edith. Mary admits that she is ready to apologize but doesn't know why Edith would accept it.
At The Sketch, Mrs. Cassandra Jones the advice columnist arrives, and turns out to be Spratt, to Edith's and Laura's shock and bemusement.
Mary goes to visit Matthew's grave. She admits that she loves Henry but she wants to feel that Matthew is happy for her. She promises that however much she loves Henry, she'll always love Matthew. Crying, she kisses her hand and presses it to the grave. She encounters Mrs. Crawley. Isobel confirms that she is delighted for Mary, when Mary confirms she is intending to re-marry.
The Crawleys have tea at Mrs. Patmore's and insist that they definitely want to make the public appearance and be photographed by the papers.
Henry arrives at Downton. Tom leaves the two alone. Mary explains that she realizes she was wrong, they are in love. They reconcile and agree to marry that Saturday. They kiss.
The Crawleys pose for a picture with an ecstatic Mrs. Patmore outside of the B&B.
Everyone gets ready for Mary's wedding. Tom, acting as best man, and Henry head off to church. Edith shocks everyone by showing up at the house. She and Mary are left alone and they reconcile. Edith assures Mary that Matthew would be pleased for her, and she compliments Mary's dress.
Mary and Henry are married in a medium-sized ceremony, with all of the family and servants surrounding them. The family discuss Edith's future, and Robert is confident that Edith still has surprises in store.
Edith watches the children and smiles as they play near Sybill's grave.