It's October 1968, and preparations for Trixie and Matthew's wedding are underway. Nancy makes a home visit to Imelda O'Connor, who is pregnant with her second child, and is surprised that Imelda, her husband Maurice and young son Paul are living in a cramped caravan on a building site. Unbeknown to Nancy, the family's circumstances quickly change when they are made homeless. When their plight is brought to the attention of Nonnatus house, Matthew is very vocal about his views.

Shelagh supports Rosemary Mason, who is expecting her fifth child with husband Arthur. They run a family business selling second-hand goods and also run a guesthouse. Shelagh is troubled by Rosemary's symptoms and consults Dr Turner, who diagnoses Rosemary with hepatitis, a condition that leads to the revelation of a family secret.

Dr Turner soon notices a worrying rise in hepatitis cases throughout the district, and when the outbreak directly impacts the residents of Nonnatus House, the team rally to care for a beloved member. Elsewhere, Cyril returns home from Jamaica and is keen to throw himself into work. He volunteers at a homeless shelter for men and meets a young stricken man, Leon, who is struggling with addiction.