It is May 1968, and the Nonnatus team are faced with challenging cases, one of which is much closer to home as Lucille struggles with her own health. At a coffee morning for expectant mothers, Sister Julienne meets heavily pregnant Lilian Reynolds, who is expecting her first child. However, after Lilian experiences some breast discomfort, she receives a devastating diagnosis.

Meanwhile, Shelagh is organising the Whitsun Maypole celebrations at the eleventh hour. She enlists Cyril, Fred, Dr Turner, Sister Monica Joan, Sister Veronica, Nancy, Violet and Miss Higgins to help, but the preparations for a Maypole dance routine are far from smooth.