Nonnatus House experiences a very busy spell and Sister Winifred’s eyes are opened to Poplar’s seedy underworld, when she cares for Bridget Cole, an expectant prostitute. Horrified by the girl’s lack of awareness, Sister Winifred draws on her past teaching experience and help from SGT Noakes to promote ‘safe sex’ to the working girls of Poplar.

Meanwhile, Barbara struggles to understand why expectant father Frank Robbins would put undue pressure on his wife to bear him a son.

Elsewhere, Sister Monica Joan feels increasingly redundant and side-lined as the busy midwives go about their work until she finds herself unexpectedly assisting Shelagh with an emergency birth.