Senior members of the convent embark on a mercy mission, swapping the snowy East End of London for Hong Kong and getting a chance to take flight and work out what really matters. For her part, Sister Julienne suddenly finds herself excited about the Order’s future. After years of battling change, she decides to embrace it and see what love can do.

Nancy’s wedding plans take a surprising turn. Sister Catherine takes her First Vows.

Joyce faces a disciplinary hearing over a recent complaint which has been upheld.

It's September 1970 and the local dustbin strike leads to a refuse site established outside Nonnatus House. With Rosalind unwell, Joyce takes over her rounds, including a visit to a rude patient who resents being examined by her.

The Nonnatus team oversee the care of a man living inside an iron lung.

The sisters welcome a new postulant, Sister Catherine, to Nonnatus House.

Rosalind delivers a baby with a suspicious spinal lesion. A sudden gas explosion shocks all.

Trixie cares for a single mother recently discharged from a psychiatric hospital.

Protests on the Isle of Dogs cause chaos for the Nonnatus team, while an apparent immaculate conception concerns the midwives. Sister Julienne and Trixie plan to fight back the Board of Health’s disapproval of the way Nonnatus House operates.

It’s Christmas 1969, and the funfair and carol concert add color to frosty Poplar in wintertime.