A group from Nonnatus House travels overseas in order to assist a struggling clinic in South Africa.

The Nonnatus House staff face great change, Phyllis and Barbara help a battered wife, while Sister Mary Cynthia becomes increasingly fragile.

An explosion at the docks badly affects the husband of a new mother, Patsy feels under pressure, and Sister Ursula continues to test the patience of everyone at Nonnatus House.

Sister Ursula continues to make life difficult for the staff of Nonnatus House, while sweeping reforms place the maternity unit under threat.

Nonnatus House advertises for a new midwife, while Trixie, Sister Winifred and Tom help an expectant mother in a difficult situation.

Nonnatus House welcomes a new recruit, Fred and Violet take in a vulnerable young man, Sister Monica Joan makes a discovery, and Trixie meets a charming dentist.

As the Cuban Missile Crisis brings fear to Poplar, Sister Julienne tries to arrange the return of Sister Mary Cynthia, while Valerie deals with a very challenging case.

The effects of thalidomide continue to take their toll on a former patient, leaving Patrick guilt-ridden, while a shocking incident leaves Phyllis consumed with guilt of her own.