A pregnant mother with a chronic heart condition falls unwell, Nancy grows suspicious of a young father’s erratic behaviour, and Matthew prepares for a visit from his father.

The maternity home is thrown into chaos by an outbreak of gastroenteritis, and Nurse Crane fights to save her career. Meanwhile, Cyril encourages Reggie to seek help.

Thomas Shelby’s wedding day has arrived at last, but while his guests enjoy the celebrations he has important business to conduct, as a mysterious stranger makes their presence known.