Dr Turner and Nurse Crane must deal with an alarming outbreak of diphtheria. Fred finds an abandoned baby in a dustbin, and the team must help locate its mother.
Lucille is seconded to St Cuthbert's when a ward sister is off sick, but a lift malfunction sees her spend the evening with mother-to- be Connie instead of her planned rendezvous with Cyril.
Demolition work in Poplar uncovers a long-buried secret that leads to a testing and emotional case for the team. Sister Julienne takes on a sensitive delivery.