A woman is caught stealing milk from Nonnatus House, but she pleads for mercy from sisters Julienne and Monica Joan, explaining that she has been stealing milk as she is pregnant. As Sister Julienne learns more about her, she is convinced that this woman needs help becoming the mother she wants to be. Meanwhile, Dr Turner puzzles over a mysterious string of symptoms, and the blossoming romance between Miss Higgins and Sgt Woolf is thrown into jeopardy.