When a young woman with Down's syndrome is discovered pregnant, sinister circumstances are assumed. Meanwhile, as the nuns organise celebrations for Sister Evangelina's jubilee, Nonnatus House greets new midwife Patsy. Elsewhere, Timothy Turner takes his first steps without his callipers.

As Jenny returns to Nonnatus House, her encounter with nervous expectant mum Faye forces her to break the rules. Chummy throws herself into preparations for her mother's visit, whilst Sister Julienne and Cynthia deal with acute mental illness in a newly delivered mother.