Dr. Clarkson is preparing to leave after assuring the family that Sybil's pains are normal and that birth is not yet upon them. He is unhappy that Grantham is bringing in an expert in childbirth named Sir Philip Tapsell who has presided over the births of many of the nobility. Cora isn't excited either, but Robert hasn't forgotten Clarkson's misdiagnosis of Matthew and his inability to save Lavinia Swire. Cora reminds him that Clarkson has been treating the girls their entire lives and knows their medical history better than Sir Philip does.
Downstairs, the staff are also anxious for the birth. Carson nips any talk of babies in the bud and Daisy has the chance to give Ivy a hard time. Jimmy admits to O'Brien that he's been asked to fix the clocks, but doesn't know how. O'Brien compliments him as that's the work of a first footman. She encourages him to ask Thomas for help as he's an expert with clocks.
Sybil tells Mary how uncomfortable she is. Mary isn't going to let that stop her from wanting children of her own, but isn't ready to confess why she and Matthew haven't produced any yet. In the meantime, Sybil is a bit concerned about the baby's Christening. They'd planned to have the baby in Dublin where a Catholic ceremony would be held. Now, it's certain that the baby will be Christened here and she's not looking forward to the argument about doctrine. She does believe in God, but she's not sure that the Anglican church has all the answers. Mary promises to be on her side if it comes to a battle with Mr. Travis, the local vicar.
Thomas is gladly helping Jimmy wind the clocks in a manner that is far too close for Jimmy's comfort.
Finally able to visit her husband in prison again, Anna wonders what caused all that trouble. Bates would rather examine what she learned from Mrs. Bartlett. If Vera was preparing her evening meal when Mrs. Bartlett saw her, it means she was cooking the meal that would kill her. However, Bates was on the train back to Downton when she ate it, which means that she put the toxic ingredients into the mix that killed her. Anna realizes this means that Vera did commit suicide in a probable attempt to frame her husband for murder.
Isobel has asked Ethel to come to Crawley house because she wants to offer her a job. Ethel isn't sure that this will work out as no one will want to come visit Isobel if they know there's a former prostitute working there.
Craig and the corrupt guard, Durrant, note that Bates seems to be in good spirts and wonder what news he's gotten recently.
Matthew tries to show Mary how disheveled the farms look. Mary is defensive of her father, which Matthew understands, but insists that running them like businesses will help save them. Large estates are going under and he doesn't want Downton to be one of them.
Sir Philip arrives, full of assurances that Sybil will be fine. After dinner, Matthew pulls him aside to ask if his war injury could be preventing he and Mary from conceiving. Sir Philip asks a few discreet questions, then advises Matthew to drop his anxiety. Meanwhile, Anna takes the opportunity to tell Grantham about the news that could free Bates. They are a bit concerned, though, as Mrs. Bartlett never revealed this to the police and isn't likely to do so if she feels that it could free Bates. Grantham offers to call his lawyer, Murray, to arrange for a quick visit to Mrs. Bartlett.
Edith has been offered a job writing for the local paper. Matthew encourages her, but Robert dismisses the news as it's obvious the editor only cares about Edith's name attached to his paper. Edith points out to Matthew that her family only ever thinks of her as a failure.
Mrs. Bird will not work in the same house as Ethel and Isobel readily agrees that Mrs. Bird will have to go elsewhere. It's obviously not the resolution Mrs. Bird had wanted.
Alfred and Jimmy are flirting with Ivy who appears to fancy Jimmy a bit more than Alfred. She endures another harsh comment from Daisy.
Meanwhile, Sybil's time is coming soon. While Branson frets, Countess Violet appears, intending to stay until the baby is born. Cora insists on calling for Dr. Clarkson, but Robert reveals that Sir Philip doesn't want the birthing room crowded. As she gave her word to Clarkson, Cora isn't backing down and Edith offers to drive over to get him.
Downstairs, Alfred helps Ivy with some sauce that isn't going well. Mrs. Patmore watches the whole thing and gets a kick out of complimenting Ivy when Daisy realizes that all isn't ruined. The cook then explains privately to Daisy that mistreating Ivy isn't going to get Alfred to like her more.
Dinner conversation about Edith's possible job is disrupted when a nurse arrives to signal that labor pains have begun. Jimmy informs the downstairs staff and the wait begins.
Upstairs, things aren't going well. Dr. Clarkson is concerned that Sybil seems confused and her ankles are swollen. Sir Philip dismisses all of this as the natural part of giving birth, but Clarkson doesn't agree. Though Grantham assumes Clarkson is just suffering from wounded pride, Matthew isn't sure they should dismiss his opinion. Countess Violet agrees with Matthew and sniffs that she's not as concerned about Sir Philip's feelings as her son is.
Sir Philip has taken Clarkson into the hall to quietly chastise him for upsetting the family needlessly. Clarkson frets that Sybil may be experiencing the symptoms of eclampsia. If he's right, they need to take the baby now.
Ethel has burned Isobel's dinner, admitting she's never been much of a cook. Isobel tries to take it in stride as she knows Ethel is trying. Meanwhile, Molesley shows Carson a letter from Mrs. Bird. Carson fumes that Mrs. Crawley would allow a prostitute to work for her. Mrs. Hughes reminds him that Ethel wasn't a great cook, so that may not be an issue for long. Carson decrees that none of the servants are to set foot in Crawley House.
Sweating through labor pains, Sybil warns her husband about going backward when he suggests he take a job in Liverpool working on cars. She comments on lying back to watch the stars, alarming Branson. Clarkson wants to take a urine sample and Cora backs him up. When Sybil apologizes to Clarkson for not doing her rounds, it's clear her mind is not where it should be.
Dr. Clarkson sets out his position: Sybil is confused, her ankles are terribly swollen for a woman with small ankles, her urine contains too much protein and the baby is small. These are all signs of eclampsia. They must get her to the hospital at once for a caesarean section if they want a chance to save her. Sir Philip reminds Clarkson that they would be putting Sybil at risk for no reason as the operation would be traumatizing for her and expose her to infections common in a hospital. Grantham sides with him, but his wife and mother insist that Sybil's husband make the decision.
Downstairs, the servants know that arguing doctors are not a good sign.
Branson doesn't know which doctor to trust. Clarkson cannot promise the operation will save his wife, but he does promise that, if she is suffering from preeclampsia and they do nothing, she will certainly die. Cora is adamant that she would have taken Sybil to the hospital when this first became an issue. Sybil's screams bring them all to her room.
At Crawley House, Isobel and Ethel worry over Sybil even as Isobel has a hard time stomaching the tea Ethel just delivered.
Mary comes down to the library to let everyone know that Sybil has had a girl. Both are fine. Upstairs, Tom sits with his wife and baby. Sybil is tired, so everyone leaves except Cora. Sybil asks her mother to make sure that Tom doesn't go to work on cars in Liverpool. She fears her father will see that as a solution when she knows it's wrong for Tom. Cora promises to support her daughter when the time comes.
A chagrined Clarkson apologizes to Sir Philip who allows that no harm was done and advises they all go to bed. Downstairs, Carson gives the news to a relieved staff and dismisses them to their own beds. Jimmy notes Thomas's happy look and is told that Thomas worked with Sybil in the hospital and thinks a great deal of her. Thomas uses the opportunity to touch Jimmy's hand and compliment him before he leaves. Jimmy confides to O'Brien that he is uncomfortable with all of this touching that the valet does. O'Brien reminds him that Thomas has the ear of the Earl. If Jimmy can get along with him, it's good for his prospects here.
In the night, Mary races to her parents' bedroom to frantically wake up her mother. Soon, chaos reigns in Sybil's bedroom as Robert angrily confronts Sir Philip about his assurances while Clarkson sadly confirms that it is eclampsia and nothing can be done now. Matthew is incredulous that medical advances cannot assist Sybil who is complaining of an aching headache and falls into seizures while her distraught mother and husband reach out to her. When she becomes catatonic, Mary realizes she's stopped breathing. Clarkson confirms her death. The sad scene is punctuated by the cries of her newborn baby from another room.
Having awakened the downstairs staff, Carson relates the unhappy news and advises them to carry on as they would normally. Daisy weeps in Mrs. Hughes's arms, then Thomas steps out into the hall to break down by the stairs. He tells Anna that few people in this world have ever been kind to him, but Sybil was one. Mrs. Hughes appears briefly, before admitting she will be doing some crying herself and moves on to make sure Carson is alright. Carson cannot get past how a young woman he's known since birth is gone.
Cora's distress has been replaced by an eerie calm as she sits by her daughter's bed and talks to her, promising they will look after her husband and child. Mary urges her to get some rest, but Cora will only continue to talk to her youngest child. She tells Mary to ask her father to sleep in his dressing room.
The next morning, Murray arrives, not having heard about Sybil's death. Matthew admits that Lord Grantham is in no condition to greet him today, but, he does ask that, after Murray speaks with Anna, if he could take the opportunity to have a word with the lawyer. Anna tells Murray everything Mrs. Bartlett told her.
When the undertakers arrive, Mary and Edith kiss their sister goodbye. Edith wonders if they might, as the two surviving sisters, be nicer to each other. Mary doubts they can do that, but, since they will not see Sybil again in this life, they should at least love each other as they should for now. They embrace and look to Branson.
Matthew gets his chance alone with Murray who is relieved that someone in this house understands that manors are on their way out. Mary discovers them meeting and is furious that this discussion is taking place behind her father's back, especially when he's in no condition to defend himself. Murray assures her he only came to meet with Anna to get some information that could save her husband. Mary does agree that this house could use some good news, but is still unhappy that her husband is plotting to take her father's estate away on the same day his youngest child was taken from him.
In prison, Murray gives the news to Bates about Sybil and tells him he'll be visiting Mrs. Bartlett to get her statement before taking it to the police. Having gotten into Bates' letters, Craig and Durrant watch from afar and agree that the lawyer won't be happy when he contacts Mrs. Bartlett.
Countess Violet arrives in black, agreeing with Carson that it is the worst thing they've been through together. Fraily, she walks on her own to comfort her family who have gathered in the sitting room. Tom is upstairs, refusing food, a nurse has been got for the baby and Cora is insistent that she write to Dr. Clarkson to apologize that he wasn't believed when they could've saved Sybil. She is clear that she blames Sir Philip and Robert for thinking they knew more than he did.
Not having been there the night before, Violet asks her son what happened. Robert can only admit that there is truth in what she said. Violet reminds him that no one is to blame for what happened. They need to cherish his daughter's memory. Upstairs, Branson stands at the window, looking out over Downton and holding his baby.