Dr Turner is horrified to realise he may be partly to blame as the cause of the recent rise in birth deformities comes to light, and tries to prevent further cases. Sister Evangelina returns to work, but has clearly been affected badly by her stroke, and her health continues to deteriorate. A pregnant bride goes into labour during her wedding reception, while her mother is forced to come to terms with her grandchild being conceived out of wedlock.

Jenny is assigned to first-time mother Jeanette, who requires frequent visits during a protracted labour, and when she meets her patient's cousin, Philip, a new friendship begins to grow for the midwife. Meanwhile, Chummy worries about her mother's illness when she discovers Lady Browne has discharged herself from hospital.

Nonnatus House faces its darkest day after a tragic incident in the heart of Poplar. As the community rallies together, the team must overcome personal anguish to help the injured.

The convent comes under threat of demolition. Fred's pregnant daughter and her young son come and stay with him. Jenny is wooed by a new love interest. Chummy and PC Noakes prepare for the arrival of their baby.

Jenny has an eventful few days, starting with a patient who as well as having herself to worry about, is also struggling to cope with her mother, an agoraphobic who hasn't been outside for at least 12 years. On top of that, Alec asks the midwife to accompany him to Brighton for the weekend, leaving her wondering if his intentions are strictly honourable. However, things soon take a tragic turn. Meanwhile, Shelagh joins the local choir to take her mind off her problems.

Poplar is rocked by a series of violent attacks on women, and a prostitute is too ashamed to report what she knows - but her actions lead to a dangerous man roaming the streets, with devastating consequences for the residents of Nonnatus House. A mother tries to keep her daughter's pregnancy a secret to avoid gossip, putting her life in danger. The Turners go on a long overdue holiday, but the weather ruins their plans.

Dr Turner experiences the biggest test of his career, while Trixie’s approaching nuptials cause stress levels to escalate. Sister Julienne hatches a plan to save Nonnatus House.

The nuns and midwives are busy preparing for Sister Evangelina's surprise jubilee celebrations, marking 50 years since she took her vows, but a face from the past threatens to ruin the party for the guest of honour. It's back to business when a young woman with Down's syndrome is brought in feeling unwell. To everyone's surprise, they discover she is six months pregnant, causing some of them to think the worst, and the staff are joined by new nurse Patsy, whose sense of humour and no-nonsense attitude make her an instant hit.

An unexpected turn of events leads to a wedding being hastily arranged. Shelagh finally goes into labour. The arrival of the pill leads to unforeseen consequences.

Nonnatus House struggles to come to terms with Nancy’s revelation. With Sister Julienne taking her annual leave at the Mother House, Sister Hilda relishes the chance to cover and impress with her leadership. While attending an expectant mother, Sister Frances and Trixie are appalled to learn that Poplar’s housing crisis is worsening, leaving the Nonnatus team vowing to fight for change. It’s a poignant time for the Turner family as Timothy readies to leave for medical school in Edinburgh and Cyril receives news from home, prompting him and Lucille to consider their own future. Meanwhile, a very special baby is born, who causes a rift in a close-knit family and leads many people to count their blessings.

Nonnatus House suffers its biggest threat yet. But this time it’s not the bricks and mortar that are in danger, it’s the people.

Nurse Crane helps a struggling first-time mother accept her baby’s birth defect, and Violet’s bid to be mayor is thrown into turmoil by unforeseen circumstances.

Nonnatus House welcomes a new recruit, Nurse Valerie Dyer. A vulnerable young man captures Fred and Violet's hearts, whilst the whereabouts of Sister Mary Cynthia is a concern.

Lucille helps elderly hoarder Clarice Millgrove who is struggling to keep her independence; Sister Hilda and the team work hard to help a Ghanaian family with an undiagnosed illness; Violet puts herself forward in the upcoming elections.

Dr Turner and Nurse Crane must deal with an alarming outbreak of diphtheria. Fred finds an abandoned baby in a dustbin, and the team must help locate its mother.

At the Turners, Shelagh receives a phone call from the Hong Kong adoption agency, which has the alarming news that someone from May's past has arrived in the UK and wants to see the little girl.

Sister Julienne decides it is time to take matters in hand when a letter arrives from the council saying that it will cut funding to Nonnatus House and no longer pay for the accommodation, and goes to see Violet at one of her open sessions as a local councillor.

Miss Higgins receives an unexpected visitor, and Sister Monica ruffles feathers. Poplar votes for its Mother of the Year.

Doctor Turner is concerned by the spread of tuberculosis in the community, Jenny tries to repair a father and daughter's fractured relationship, and Sister Bernadette receives devastating news.

Trixie's feathers are ruffled when Jenny is promoted, but the new Acting Sister has more to worry about after a mother-to-be reveals the baby she is carrying doesn't belong to her husband - and to complicate matters, the real father is black. Cynthia is inspired by a lecture on natural childbirth, convinced it will help an overly anxious patient, while Alec and his friends try to persuade Jenny to join them on a CND march.

Sister Julienne receives an SOS from Holloway Prison, whose usual maternity workers have been struck down by illness, and when she and Trixie step in to help, the nun puts her reputation on the line to prevent a heavily pregnant convict having her unborn baby taken away by social services. Shelagh faces heartache when a routine pregnancy check reveals something far more serious, Alec has a confession for Jenny and Fred takes the gang to the theatre to celebrate Chummy's birthday - only for the trip to end in disaster.

Sister Julienne calms an anxious new mother who has put her baby in danger. Jenny, seconded to The London, is impressed with the facilities, but soon begins to see cracks in the establishment. Chummy is upset to learn that her mother has walked out on her father, leaving Lady Browne penniless. As Dr. Turner and Shelagh continue the adoption process, they uncover a devastating secret.

Barbara faces her most challenging case to date when she treats first-time mother Abigail Bissette and the birth does not go according to plan. As Sister Julienne struggles with the increasing financial pressure on Nonnatus House, a mystery benefactor comes to the rescue. Elsewhere Sister Evangelina is unimpressed by newly arrived nurse Phyllis Crane.

When a baby is born with severe deformities of the kind later identified as caused by the drug thalidomide, the midwives find it difficult to handle the situation, and the baby's father rejects her completely, to his wife's dismay. Trixie's new sideline as a keep fit instructor brings her into conflict with Sister Julienne, and she also becomes suspicious of the relationship between Barbara and Tom. Rather than return to Wales as her mother wishes, Delia moves into Nonnatus House.

Dr Turner helps the Mullucks cope with the stresses of caring for a disabled child as the terrible legacy of thalidomide becomes apparent and Nurse Crane faces an unexpected crisis.