It’s a busy holiday season at Nonnatus House. Not only is Lucille marrying Cyril on Boxing Day and Mother Mildred on her way to visit; St. Cuthbert’s has referred twenty extra patients to Nonnatus, half of whom are due before Christmas. As Violet obsesses over Lucille’s dress and the Nonnatans plan the wedding with Lucille’s church, the midwives meet their new patients.
Mrs. Howells is on her fifth baby and is admitted to the clinic for bed rest by Dr. Turner, despite Shelagh’s fear that they won’t have enough room. Susan Chu is upset that she will have to give birth at home rather than at the hospital. Anita Page is underweight and flees the clinic when Sister Julienne wants to take more tests.
Dr. Turner, with his medical student son Tim in tow, runs into Anita at her home when her husband Charlie calls him to attend to neck pain: one of his petty criminal associates has been cut with a knife. Dr. Turner treats the wound. When he and Tim leave, Tim observes that Anita looked scared of Dr. Turner.
Esme Bolton is happy to give birth at home, since her landlord has recently been improving the place, replacing the sink and fumigating the cockroaches. Trixie runs into the landlord while attending Esme: it’s Matthew Aylward, doing his best to fix up his family’s tenement houses. He waits for Trixie to deliver Esme’s baby, then walks her home, discussing his upcoming first Christmas without his wife Fiona. Trixie encourages him to attend Lucille’s wedding, which he has been invited to as Nonnatus’s benefactor.
The approaching wedding has Phyllis missing the late Barbara, for whom she served as a bridesmaid. Lucille will have no bridal party, since her sisters are back home in Jamaica—although she does at least have her grandmother’s locket with photos of her parents on their wedding day inside. Phyllis admits to Lucille that she bought pearls for Barbara’s wedding, and has never worn them since.
Sister Hilda hosts a bachelorette party for Lucille enlivened by some rum-spiked punch, courtesy of an elaborate gift basket sent by Charlie Page in gratitude to Dr. Turner, to the doctor’s chagrin. Lucille drunkenly trips on her way upstairs to bed and wakes the next morning with a black eye—three days before the wedding. Her eye swells up with a hematoma, prompting Dr. Turner to send her to the hospital, from which she returns with the bad news that the swelling will go down on its own—in a week or longer. Lucille won’t let Cyril see her and says that they can’t hold the wedding.
Sister Monica Joan suggests an old-fashioned solution: leeches. Dr. Turner applies one to Lucille’s eye, leaving it to feed on the blood under the lid. When it is removed, the swelling has gone down. The wedding will go on.
It does require some adjustments. The man from Lucile’s church who was to walk her down the aisle has broken his shoulder, so Cyril suggests she ask Fred to step in—he is Cyril’s best man, since he was Cyril’s first English friend. After a night building a snowman with Lucille and Reggie, who is reveling in the snow, Cyril asks Reggie to be his new best man—Reggie has already attended the bachelor party and picked out a fancy silk tie.
Anita Page’s water breaks, but when she arrives home to a dinner cooked for her by the caring Charlie, she acts as if nothing has happened. She has also been avoiding check-ups at the maternity clinic. Only a day later, when the pain becomes unbearable, does she go to Nonnatus. Phyllis immediately drives her to the clinic, and Trixie delivers an undersized girl. Anita refuses to breastfeed her. Charlie is overjoyed at the birth.
Trixie is working the clinic on Christmas Day while everyone else celebrates at Nonnatus House and prepares for the wedding, but soon the other midwives are called off to work. Sister Francis attends Susan Chu at home. When she realizes the baby is breach, she calls for reinforcements, but everyone is busy. She has to deliver the baby—her first breach alone—by herself, and does so safely with the help of Susan’s husband.
Trixie calls Dr. Turner in to check on Anita’s baby, who isn’t feeding and won’t stop crying, and Anita, who isn’t doing well. He quickly understands Anita’s condition: she’s addicted to heroin and is suffering withdrawal—and so is her newborn. He begins to wean Anita off the heroin with a prescribed opiate, but has never dealt with the condition in a newborn before.
Luckily, Shelagh and Mother Mildred arrive at the clinic with holiday meals for all the workers, and Mother Mildred has dealt with opium addiction in infants from her time working in Hong Kong. Dr. Turner and Shelagh’s adopted daughter May was one such baby. Shelagh hates that she wasn’t there for May in her early life, and volunteers to watch over Anita’s baby and wean her off the addiction.
Dr. Turner is pulled away to help Sister Hilda as she attends to Maria Kaufopolous, who is hemorrhaging. After Sister Julienne gives the baby oxygen, both Maria and her baby are sent to the hospital, where they receive transfusions.
Then Dr. Turner is off to Mrs. Howells, whose delivery is taking too long and requires forceps. Tim observes and is handed the infant as his father rushes off to help another patient.
Anita’s baby may be taken away by the welfare office because of her addiction. She herself nearly suffered the same fate, as her mother was an alcoholic. But her mother needed her; Anita witnessed her death when she was only eleven years old. Charlie saved her, she says, but he doesn’t know about her addiction: his brother died of heroin because Charlie was afraid to bring him to the hospital since the drug is illegal. Charlie hates drugs as a result, as he showed when he rushed one of his associates in to Dr. Turner after he overdosed on heroin. When Anita admits her addiction to him, he tells her he doesn’t want to miss her like he does his brother, and that he and their newborn need her to kick the habit.
Back at Nonnatus, Mother Mildred is entertaining the Turner children along with the pupil midwife Nancy and her daughter Colette by reading A Christmas Carol aloud. Slowly, all the midwives file in after a full day’s labor and sit to listen.
The next day, Phyllis finds a wrapped box waiting for her. It’s her pearls, with a note from Lucille asking her to wear them at the wedding, for Barbara. Phyllis has her own surprise for Lucille, cooked up with Miss Higgins: a bridal party made up of young children Lucille has delivered. Their mothers made outfits for them, and said they would never forget Lucille.
The wedding car has broken down, but this final snag is overcome when Trixie calls Matthew to chauffeur Lucille and Cyril. Lucille’s dress is Violet’s masterpiece, with holly hidden in the lace. The ladies of Lucille’s church incorporate a Jamaican tradition at the reception in the maternity clinic, and when the festivities are over, Cyril and Lucille retire to their home together above the Buckles’ general store. A new life is before them.