Carole Reece is struggling with her baby Dean. Only fifteen years old—she’s accompanied by her foster mother to the clinic—Carole can’t stop him from crying. Sister Frances delivered Dean, so Carole asks Frances to join her in Dean’s exam. The boy has eczema, which is easy enough to treat with lotion, but Frances offers to stop by a few days later to see how Carole and Dean are getting on.
She coaches and comforts Carole in her inexperience, then talks to her foster mother. Carole, like many children the mother has fostered, is sensitive and insecure: in her case, partly because her mother always disappeared whenever a new man showed up. The foster mother worries that Carole might end up in a similar situation: she already has constant male callers. Carole is due to receive her own council flat when turns 16—what will happen when her foster parents aren’t around to turn the young men away?
Dr. Turner suggests to Sister Frances that Carole might benefit from an IUD, so that she doesn’t have to worry about taking the pill on top of everything else. But when Frances joins Carole in touring her dingy one-room flat, which Carole is eager to occupy, and brings up the IUD, Carole responds that she doesn’t need one; she’s done with men.
Nancy sympathizes with Carole, as a fellow young mother brought up without biological parents. Sister Hilda and Sister Julienne want Nancy to begin taking on more responsibility in order to show her what she’s capable of, rather than chastise her for her absentmindedness. But the first day that Nancy is in charge of morning assignments for the midwives, her alarm doesn’t go off and she oversleeps, to Hilda’s disappointment.
But she eventually picks up the slack, enough that Julienne invites her to join Dr. Turner and Julienne herself at a midwifery conference. Shelagh was supposed to attend, but Tim has come down with a fever and is staying at home to recuperate. He keeps exhausting himself trying to study for his medical degree, so Shelagh wants to stay home with him.
Nancy accepts Julienne’s offer but is conflicted, as she testily explains to Sister Hilda. She’ll have to miss her day off, which she always spends with her daughter Colette. She has to choose between what’s good for her and what’s good for Colette, and doesn’t feel like that’s fair. Hilda later tells Nancy that she understands her conflict—even though Nancy has now decided that Hilda was right and she should go to the conference. Hilda offers Nancy her own day off so that she can attend and still spend a day with Colette.
Sister Hilda is also helping Edina Corbett, who is having painful joint problems in the late stages of her pregnancy. The pain is so great that she mistakes it for contractions one evening. Edina and her husband Lionel have a ten-year-old daughter; Lionel, a train operator, now worries that he’s too old to be a good parent. Edina wants him to get new glasses, because his current ones are causing headaches.
When Edina’s daughter bangs on the door of Nonnatus House one morning because her mother can’t get out of bed due to the pain, Hilda sends Edina to the clinic to rest until she gives birth—it will also allow Lionel to sleep better at night.
Tim is constantly falling asleep while studying. Dr. Turner chastises him for not getting enough rest to recover from his fever, and Tim lashes out at his father. He’s tired of being treated like a child. The next day, Shelagh tells Tim that his father still defended him when she got annoyed with him—he loves Tim more than anything. Tim must apologize.
Sister Frances is worried about Carole since she’s little more than a child. Like her son, Carole is now incessantly itchy and Frances can’t figure out the cause. Worried that Carole is lonely in her new flat, Frances brings Dean to Nonnatus House to allow Carole to go to a dance. Sister Julienne warns Frances not to make a habit of such babysitting, and to try to make Carole take on some more responsibility of her own. Carole picks up Dean late and lashes out at Frances because she’s upset after a fight with a boy.
Still worried about Carole’s itching, Frances brings Dr. Turner to Carole’s flat, where they find her unconscious on the ground. She rouses and says she only remembers falling. Dr. Turner calls an ambulance.
At the hospital, Frances learns that Carole is pregnant—and far along. Carole wanted to wish it away. The fight she had was with the new father, who wants nothing to do with a child, just like Dean’s father.
Carole soon goes into labor, prematurely. She begs Sister Frances to stay with her for the labor, and Frances convinces the hospital midwife to let her stay for emotional support. When the baby is born, the midwife immediately calls for oxygen.
Edina’s labor has also finally started, although it’s slow going. Lionel is working, but his train back to London is on schedule, so he might be home in time for the birth.
Nancy, Sister Julienne, and Dr. Turner are taking Lionel’s train back from their conference, which Nancy loved—she’s eager to learn about new technologies and medical possibilities. The train is full of rowdy football fans, but there’s also a kind worker who had nine children under the care of the Nonnatans: she remembers both Sister Julienne and Dr. Turner, and comps their tea while Nancy uses the ladies’ room.
Violet is having her own hot beverage at the café in Poplar when she runs into Matthew, who is writing a letter to Trixie. He admits to Violet that they have been corresponding frequently, and at length.
Lionel is tired at the controls of the train. Then he starts to have an attack of some sort, and accidentally speeds up the train through a red light as he loses consciousness. It collides into another train just outside Poplar, setting off an explosion that rocks Lucille and Cyril’s church, sending shrapnel everywhere—including a shard of glass into Mrs. Wallace’s eye.
Fred, Matthew, and Lucille immediately take charge: Matthew and Lucille gather injured people towards Nonnatus, where they can set up a medical station, while Fred rallies his defense corps. Back on the train, Nancy is still on her feet and stumbles out of the restroom but can’t open the door to the car containing Dr. Turner and Sister Julienne. She desperately tries to reach them but is pulled away by a football fan—it’s too dangerous to stay near the train lest another explosion occur.