Mary is forced into a difficult position by an unwelcome visitor, while Mrs Hughes looks to ease her worries about marrying Carson.
An outburst threatens Bertie and Edith's relationship, while Mary makes a decision over her feelings for Henry.
Everyone is left shocked by the transformation of a figure from the past, while Anna and Mary head to London to deal with an emergency.
Violet attempts to bring the Minister of Health into the hospital dispute, but his visit is overshadowed by a sudden medical emergency.
The big day has finally arrived for Mrs Hughes and Carson, while Edith is forced to rely on an old friend after she grows weary of her editor's constant insults.