Sister Catherine is distressed when a newborn baby is taken from the maternity home. Sister Julienne shares some news with the Turners and Sister Veronica about Christopher’s father.

New postulant Sister Catherine arrives at Nonnatus House. Disappointment strikes as responses for the measles vaccination clinic remain low. Dr. Turner suggests sterilization to a mother of seven if she no longer wants any more children.

It’s July 1966, and Britain is in the grip of World Cup fever. Nonnatus House awaits the arrival of four new pupil midwives. One of them, Nancy Corrigan, makes quite an impact. Cyril and Lucille’s relationship continues to blossom.

A heatwave descends over Poplar and Sister Monica Joan struggles. An angel comes in the form of Fred, who has a sneaky plan. While Cyril continues to search for a new job, Lucille comes to terms with unexpected news.

Join the cooks as they prepare grab-and-go meals, from breakfast burritos to musubi. In the second round, the cooks make home-baked treats as part of the first-ever Great American Recipe Bake Sale.

The pupil midwives reach their third month of training. An anxious Trixie receives an urgent phone call that leads to dire consequences for her patient. Elsewhere, the Turner’s Apollo 11 moon landing party is in full swing at Nonnatus House.

Following a visit to the Crabtree’s Farm, Carmody is challenged with learning how to be a vet outside of his books. The new farmers have a worrying illness amongst their herd and James wants to help them in any way he can. Helen rallies the community to help the newcomers whilst she waits for some personal news.

While Tristan gives Tricki-Woo the spa treatment, James deals with Helen’s champion bull. Siegfried makes a decision about Tristan.

Tristan works out how to make clients happy but then receives some bad news. James and Helen have a heart-to-heart.

TB testing mistakenly puts a prize cow in danger. Helen struggles with her lifelong vocation. Mrs. Hall and Tristan have brushes with love.

Nurse Crane is shocked when her fitness comes into question during a ventouse training course. Trixie cares for a Hindu mother and her newborn twins, but it’s not long before an emergency gastroenteritis outbreak is declared at the maternity home.

Charlotte and Sidney clash over Miss Lambe’s love life, and Charlotte strikes up a new friendship. At Denham House, Clara witnesses a scene that raises her suspicions. Lord Babington makes his romantic intentions known, but faces being rebuffed.

Tension mounts for Charlotte when Colbourne and Colonel Lennox reunite at Lady Denham’s garden party.

Charlotte attempts to distance herself from Colbourne but as they are repeatedly thrown into each other’s orbit, their chemistry rises. Meanwhile Georgiana is unravelling and makes a surprising decision to protect herself.