It is December 1967, and with Christmas fast approaching, life in Poplar is returning to normal after the terrible train crash.

The midwives move the maternity clinic into new premises and are delighted when one of their first patients through the door is Rhoda Mullocks, who the team know well. Rhoda is heavily pregnant and understandably nervous after her last baby was born with limbs affected by Thalidomide.

Nurse Crane cares for a heavily pregnant single mother, recently released from prison, while Sister Frances is called out to deliver a Sylheti mother's child in a garment factory in a rough area of Poplar.

Meanwhile, Fred decides that Poplar needs to come together to raise money for those families still affected by the train crash and pitches the wonderful idea of a festive talent show – Poplartunity Knocks!

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.

An unforeseen event in Poplar means that 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.

Sister Frances takes charge of a spirited young teenage mother who is shortly to move out of foster care and into her own accommodation. While Sister Frances strives to prepare her, things take a serious turn with the young mother's health.

Sister Hilda and Sister Julienne expect more from Nancy and decide to show her what she is capable of by letting her lead morning orders, and Timothy returns home from university after falling ill with glandular fever.

It's October 1967, which brings new beginnings with Nurse Crane away on an exciting adventure of a lifetime and Trixie taking care of her godmother in Portofino. Sister Hilda runs a tight ship, and Shelagh has joined the team to ease their busy workload. Lucille prepares for her first day back at work but is clearly not coping well, despite the support of the team.

Sister Monica Joan is spooked to find a black raven in the parlour, believing its presence to be an omen. Seeking interpretation of the raven's meaning, Sister Monica Joan connects with Dulcie Greenhlagh, an eccentric East End clairvoyant, but soon realises there is another reason they were destined to meet.

Matthew discovers one of his warehouses is being used by squatters, including a heavily pregnant woman. Shelagh faces the most challenging delivery of her career. Dr Turner attends a district health committee meeting on measles vaccination. He hopes to increase uptake by running a pilot scheme in Poplar.

It's September 1967. Trixie has been assigned to a complicated case involving a crane driver who was injured in a workplace accident and is now paraplegic. He has been discharged from hospital, and is living back at home with his wife and children. Meanwhile, Nancy and Sister Frances give a talk on the facts of life at a primary school, and Lucille's attendance at a straightforward delivery takes a distressing turn.

Shelagh decides to organise a jumble sale to raise money to fix some broken playground equipment in the park. When Sister Julienne finds a suspicious item, chaos ensues.

It's the summer of 1967, and a heatwave descends over Poplar. Sister Hilda and Dr Turner support a young father with a lung condition, and Trixie takes the lead with a struggling first-time mother. Cyril continues to search for a new job that will put his civil engineering qualification to use and pay more so he and Lucille can afford a house deposit, but Lucille receives unexpected news that she must break to him. Meanwhile, Trixie and Matthew's relationship is going well, but Trixie wants a little more romance.

It's June 1967, and the Order of St Raymond Nonnatus are celebrating a very special milestone birthday. It has been 100 years since the Order first arrived in Poplar. When Sister Julienne is unable to organise the celebrations, Shelagh brings the community together for what will be a joyous occasion.

While tending to a patient who has tuberculosis, Sister Frances and Nancy learn that some residents have become increasingly frustrated by the presence of meths drinkers in the area. As local councillor, Violet must balance her professional and personal views in how best to tackle the issue. However, Nancy begins to see past the community's fear and recognises the plight of these homeless addicts.

Trixie and Sister Frances put their training into action as they join Dr Turner at the monthly cytology clinic, which is attracting a high number of patients for a routine cervical smear test. While there, Sister Frances examines a newly married woman who presents some troubling symptoms.

Lucille helps Vivien, a single mother of three, through her fourth pregnancy and intervenes when local authorities question Vivien's capabilities as a mother. After suffering a traumatic experience, Miss Higgins is offered a place to stay at Nonnatus House, and Sister Hilda and Shelagh take the lead in the fight against a scabies epidemic that has quickly engulfed Poplar.

It's Easter 1967, and celebrations are underway for a colourful Easter bonnet parade outside Nonnatus House. Sister Monica Joan and Reggie are excited about the Eurovision song contest, while Cyril and Lucille settle into blissful married life. After taking some time away following the death of their newborn son, Derek and Audrey Fleming return to Poplar with good news - Audrey is pregnant again.

During demolition work at a nearby tenement block, the builders make a shocking discovery. The news ripples through the community, and the police are called in. The trail leads to someone close to home and has a heartbreaking effect on the team.